Light emitting diode and light emitting device including the same

ABSTRACT

Disclosed herein is a light emitting device. The light emitting device is provided to include a light emitting structure, a first electrode pad, a second electrode pad and a heat dissipation pad, and a substrate on which the light emitting diode is mounted. The substrate includes a base; an insulation pattern formed on the base; and a conductive pattern disposed on the insulation pattern. The base includes a post and a groove separating the post from the conductive pattern. An upper surface of the post is placed lower than an upper surface of the conductive pattern, the heat dissipation pad contacts the upper surface of the post, and the first electrode pad and the second electrode pad contact the conductive pattern. With this structure, the light emitting device has excellent properties in terms of electrical stability and heat dissipation efficiency.

PRIORITY CLAIMS AND CROSS-REFERENCE TO RELATED APPLICATION

This patent document is continuation-in-part of U.S. patent applicationSer. No. 14/730,087, filed on Jun. 3, 2015, which further claims thebenefits and priority of Korean Patent Application No. 10-2014-0067396,filed on Jun. 3, 2014, Korean Patent Application No. 10-2014-0091227,filed on Jul. 18, 2014, Korean Patent Application No. 10-2014-0098258,filed on Jul. 31, 2014, and Korean Patent Application No.10-2014-0124540, filed on Sep. 18, 2014. The entire disclosures of theabove applications are incorporated by reference in their entirety aspart of this document.

TECHNICAL FIELD

The disclosure of this patent document relates to light emitting diodesand light emitting devices including the same to improve luminousefficacy and heat dissipation efficiency.

BACKGROUND

For a large flip-chip type light emitting diode, current spreadingefficiency or current spreading performance is an important factorclosely related to luminous efficacy of the light emitting diode. Alarger chip area provides a higher possibility of luminous deviation inone chip, and thus current spreading efficiency or current spreadingperformance has great influence on luminous efficacy of the lightemitting diode. In order to improve current spreading efficiency (orperformance) and heat dissipation efficiency of such a large flip-chiptype light emitting diode, various electrode structures andsemiconductor layer structures have been proposed.

SUMMARY

Exemplary embodiments provide a light emitting diode capable ofminimizing reduction of a light emitting area.

Exemplary embodiments provide a light emitting diode having improvedcurrent spreading efficiency or current spreading performance.

Exemplary embodiments provide a method for manufacturing a lightemitting diode, which provides a simple manufacturing process and canimprove current spreading efficiency or current spreading performancewhile minimizing reduction in area of an active layer.

Exemplary embodiments provide a light emitting diode having improvedheat dissipation efficiency and a light emitting device including thesame.

Exemplary embodiments provide a method for manufacturing a lightemitting device having improved heat dissipation efficiency through asimple process.

Exemplary embodiments provide a light emitting diode chip incorporatinga protection device to omit a separate protection device, and a lightemitting device including the same.

Exemplary embodiments provide a light emitting device that is providedwith a light emitting diode chip including a protection device, and hasluminous uniformity and a wide beam angle.

Exemplary embodiments provide a light emitting diode having improvedheat dissipation efficiency to allow operation at high output and alight emitting device including the same.

In one aspect, a light emitting device is provided to include: asubstrate including a base and a conductive pattern disposed over thebase; and a light emitting structure including a light emittingstructure, and a first electrode pad, a second electrode pad and a heatdissipation pad extending under the light emitting structure, the lightemitting structure including: a first conductive type semiconductorlayer; an active layer disposed under the first conductive typesemiconductor layer; a second conductive type semiconductor layerdisposed under the active layer; an exposed region partially formed onthe lower surface of the first conductive type semiconductor layer bypartially removing the active layer and the second conductive typesemiconductor layer; a first electrode forming ohmic contact with thefirst conductive type semiconductor layer through the exposed region ofthe first conductive type semiconductor layer; a second electrodeforming ohmic contact with the second conductive type semiconductorlayer; and a first insulation layer partially covering the secondelectrode, wherein the first electrode pad is electrically connected tothe first electrode, the second electrode pad is electrically connectedto the second electrode, the heat dissipation pad is electricallyinsulated from the light emitting structure, the base includes a postand a groove separating the post from the conductive pattern, the heatdissipation pad contacts an upper surface of the post, and the firstelectrode pad and the second electrode pad contact the conductivepattern.

With this structure, the light emitting device has electrical stabilityand good heat dissipation efficiency.

In some implementations, the upper surface of the post may have a lowerheight than an upper surface of the conductive pattern.

In some implementations, the heat dissipation pad may have a greaterthickness than the first electrode pad and the second electrode pad.

In some implementations, the conductive pattern may include a firstconductive pattern and a second conductive pattern that are separatedfrom each other, and the first electrode pad and the second electrodepad may be disposed over the first and second conductive patterns,respectively.

In some implementations, the heat dissipation pad may be disposedbetween the first electrode pad and the second electrode pad.

In some implementations, the light emitting device may further includean insulation layer disposed between the heat dissipation pad and thelight emitting structure.

In some implementations, the substrate may further include a heatdissipation lead including an upper heat dissipation pattern disposedover the upper surface of the post, a lower heat dissipation patterndisposed over a lower surface of the base, and a heat dissipation viaformed through the base and thermally connecting the upper and lowerheat dissipation patterns to each other.

In some implementations, the substrate may further include a first leadand a second lead, the first lead including a first upper conductivepattern disposed over an upper surface of the base, a first lowerconductive pattern disposed over the lower surface of the base, and afirst via disposed through the base and electrically connecting thefirst upper conductive pattern and the first lower conductive pattern toeach other; the second lead including a second upper conductive patterndisposed over the upper surface of the base, a second lower conductivepattern disposed over the lower surface of the base, and a second viadisposed through the base and electrically connecting the second upperconductive pattern and the second lower conductive pattern to eachother; and the conductive pattern including the first upper conductivepattern and the second upper conductive pattern.

In some implementations, the light emitting structure may include afirst conductive type semiconductor layer; an active layer disposed overa lower surface of the first conductive type semiconductor layer; asecond conductive type semiconductor layer disposed over a lower surfaceof the active layer; an exposed region partially formed over the lowersurface of the first conductive type semiconductor layer by partiallyremoving the active layer and the second conductive type semiconductorlayer; a first electrode forming ohmic contact with the first conductivetype semiconductor layer through the exposed region of the firstconductive type semiconductor layer; a second electrode placed over thesecond conductive type semiconductor layer while forming ohmic contacttherewith; and a first insulation layer partially covering the secondelectrode, wherein the first electrode pad may be electrically connectedto the first electrode, the second electrode pad may be electricallyconnected to the second electrode, and the heat dissipation electrodemay be electrically insulated from the light emitting structure.

In some implementations, the light emitting structure may furtherinclude a second insulation layer partially covering the firstelectrode, and the heat dissipation electrode may be disposed over thesecond insulation layer and electrically insulated from the lightemitting structure.

In some implementations, the partially exposed region of the firstconductive type semiconductor layer may include a plurality of holesexposing the first conductive type semiconductor layer.

In some implementations, the light emitting device may further includeat least one connection hole connecting at least two of the plurality ofholes to each other.

In some implementations, the second electrode may include a plurality ofunit contact electrodes separated from each other and each including anopening exposing the hole.

In some implementations, the light emitting device may further includean extension layer electrically connecting the plurality of unit contactelectrodes to each other.

In some implementations, the light emitting structure may include atleast one mesa including the second conductive type semiconductor layerand the active layer, and the exposed region of the first conductivetype semiconductor layer may be disposed around the mesa.

In some implementations, the first electrode pad and the heatdissipation pad may be integrally formed with each other, the firstelectrode pad may contact the first conductive pattern and the uppersurface of the post, and the second electrode pad may contact the secondconductive pattern.

In some implementations, the heat dissipation pad physically contactswith the light emitting structure. In some implementations, the heatdissipation pad physically contacts with the base. In someimplementations, the first electrode pad and the second electrode padhave higher electrical conductivity than the heat dissipation pad, andthe heat dissipation pad has higher thermal conductivity than the firstelectrode pad and the second electrode pad. In some implementations, thebase includes a metallic material including Ag, Cu, Au, Al, or Mo. Insome implementations, the upper surface of the post is flush with anupper surface of the conductive pattern.

According to the exemplary embodiments, a light emitting diode includinga structure forming ohmic contact with a first conductive typesemiconductor layer through a plurality of holes to minimize reductionin light emitting area is provided. In addition, a light emitting diodehaving improved current spreading efficiency (or performance) andluminous uniformity is provided. Further, a method for manufacturing alight emitting diode, which can simplify manufacture of the lightemitting diode through simultaneous formation of part of a firstelectrode and part of a second electrode, is provided.

Further, according to the exemplary embodiments, a light emitting diodeincluding a heat dissipation electrode having relatively high thermalconductivity to improve heat dissipation efficiency and a light emittingdevice including the same are provided. As a result, it is possible tosimplify the process of manufacturing a light emitting device usingbumps and heat dissipation electrode solders while improving reliabilityof the manufactured light emitting device.

Further, according to the exemplary embodiments, a light emitting diodechip incorporating a protective diode is provided, thereby eliminating aneed for a separate protective circuit in the light emitting device. Asa result, the exemplary embodiments can reduce manufacturing costs ofthe light emitting device while simplifying the manufacture process,thereby improving yield. Furthermore, a light emitting device in which aprotective diode region PR corresponding to a dark portion of a lightemitting diode chip is vertically aligned with a center of an upperconcave section of a lens is provided. With this structure, the lightemitting device can provide uniform beam distribution of light emittedthrough an upper surface of the lens, minimize reduction in luminousuniformity, which can be caused by the dark portion created by theprotective diode region in the light emitting diode chip, and can moreeffectively prevent light from concentrating on an upper portion of thecenter of the lens upon light emission of the light emitting device.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosed technology, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the disclosed technology, and together with thedescription serve to explain the principles of the disclosed technology.

FIG. 1( a) through FIG. 4 are plan views and sectional views of anexemplary light emitting diode according to some exemplary embodiments.

FIG. 5 is a plan view of an exemplary light emitting diode according tosome embodiments.

FIG. 6 is a plan view of an exemplary light emitting diode according tosome embodiments.

FIG. 7( a) through FIG. 12( b) are plan views and sectional viewsillustrating an exemplary method for manufacturing a light emittingdiode according to some embodiments.

FIG. 13 is a sectional view of an exemplary light emitting deviceaccording to some embodiments.

FIG. 14 is a sectional view illustrating an exemplary method formanufacturing a light emitting diode according to some embodiments.

FIG. 15 is a sectional view of an exemplary light emitting diodeaccording to some embodiments.

FIG. 16( a) through FIG. 18 are plan views and sectional views of anexemplary light emitting diode according to some embodiments.

FIG. 19( a) through FIG. 24( b) are plan views and sectional views of anexemplary light emitting diode chip and a method for manufacturing thesame according to some embodiments.

FIG. 25( a) and FIG. 25( b) are plan views and sectionals view of anexemplary light emitting diode chip and a method for manufacturing thesame according to some embodiments.

FIG. 26( a) and FIG. 26( b) are plan views and sectional views of anexemplary light emitting diode chip and a method for manufacturing thesame according to some embodiments.

FIG. 27 through FIG. 29 are a sectional view, a perspective view and anenlarged sectional view of an exemplary light emitting device accordingto some embodiments.

FIG. 30 is a sectional view of an exemplary light emitting deviceaccording to some embodiments.

FIG. 31 is a sectional view of an exemplary light emitting deviceaccording to some embodiments.

FIG. 32 is a sectional view of an exemplary light emitting deviceaccording to some embodiments.

FIG. 33 is a sectional view of an exemplary light emitting deviceaccording to some embodiments.

FIG. 34( a) to FIG. 37 are plan views and sectional views of anexemplary light emitting diode and an exemplary light emitting deviceaccording to some embodiments.

FIG. 38( a) to FIG. 40 are plan views and sectional views of anexemplary light emitting diode and an exemplary light emitting deviceaccording to some embodiments.

FIG. 41( a) to FIG. 43 are plan views and sectional views of anexemplary light emitting diode and an exemplary light emitting deviceaccording to some embodiments.

FIG. 44( a) to FIG. 47 are plan views and sectional views of anexemplary light emitting diode and an exemplary light emitting deviceaccording to some embodiments.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. The followingembodiments are provided by way of example so as to fully convey thespirit of the present disclosure to those skilled in the art to whichthe present disclosure pertains. Accordingly, the present disclosure isnot limited to the embodiments disclosed herein and can also beimplemented in different forms. In the drawings, widths, lengths,thicknesses, and the like of elements can be exaggerated for clarity anddescriptive purposes. When an element or layer is referred to as being“disposed above” or “disposed on” another element or layer, it can bedirectly “disposed above” or “disposed on” the other element or layer orintervening elements or layers can be present. Throughout thespecification, like reference numerals denote like elements having thesame or similar functions.

A conventional technique for improving current spreading efficiency (orperformance) and heat dissipation efficiency is to employ linearextensions, which have high resistance. Thus, there has been a limit toimprove current spreading. Moreover, since a reflective electrode isrestrictively disposed on a p-type semiconductor layer, a substantialamount of light is lost due to pads and extensions instead of beingreflected by the reflective electrode. In addition, since currentcrowding occurs depending upon locations of an N-electrode and aP-electrode, the light emitting diode has a region having very lowluminous efficacy.

However, linear extensions included in some light emitting diodes, whichhave high resistance, and thus have a limit in improvement of currentspreading. Moreover, since a reflective electrode is restrictivelydisposed on a p-type semiconductor layer, a substantial amount of lightis lost due to pads and extensions instead of being reflected by thereflective electrode. In addition, since current crowding occursdepending upon locations of an N-electrode and a P-electrode, the lightemitting diode has a region having very low luminous efficacy.

Moreover, in order to form the N-electrode, the light emitting diode hasa relatively large area through which the n-type semiconductor layer isexposed. This structure results in reduction of a light emitting area,and deteriorates overall luminous efficacy and luminous intensity of thelight emitting diode.

Moreover, in a typical light emitting device, electrodes are formed in alarge area in order to improve heat dissipation efficiency of the lightemitting diode. However, since first and second electrodes of the lightemitting diode are mounted on a secondary substrate by solder bonding, alarge area of the electrodes provides a higher possibility of electricshort in the course of solder bonding. As a result, a light emittingdevice can suffer from failure and deterioration in reliability.

Moreover, as described above, as output of the light emitting diodeincreases, there is an increasing need for anti-electrostaticcapabilities in order to prevent failure of the light emitting diode byelectrostatic discharge. In order to prevent failure of the lightemitting diode by electrostatic discharge, a separate protection device(for example, a Zener diode) is provided together with the lightemitting diode in the same package in a packaging process of the lightemitting diode. For example, Korean Patent Laid-open Publication No.10-2011-0128592 and the like disclose a light emitting diode packagethat includes a light emitting diode and a Zener diode.

However, the Zener diode is expensive and requires a mounting process,thereby causing increase in the number of packaging processes andmanufacturing costs. In addition, since the Zener diode is placed nearthe light emitting diode within the light emitting diode package, thepackage has further reduced luminous efficacy due to light absorption bythe Zener diode, thereby causing reduction in yield of the lightemitting diode package. Moreover, the light emitting diode package cansuffer from uneven light emission depending upon a location of the Zenerdiode.

FIG. 1( a) through FIG. 4 are plan views and sectional views of a lightemitting diode according to some embodiments. FIG. 2 to FIG. 4 aresectional views taken along lines A-A, B-B and C-C of FIG. 1( a),respectively. For convenience of description, FIG. 1 (a) shows an outerplane of the light emitting diode according to the exemplary embodimentand FIG. 1 (b) shows a plan view of the light emitting diode accordingto the exemplary embodiment, which includes arrangement of a secondelectrode 130. Reference numerals of components in the plan views willbe described in more detail with reference to exemplary embodimentsshown in FIG. 7 to FIG. 12.

Referring to FIG. 1( a) through FIG. 4, a light emitting diode accordingto some embodiments includes a light emitting structure 120, whichincludes a first conductive type semiconductor layer 121, an activelayer 123 and a second conductive type semiconductor layer 125, a firstelectrode 140, and a second electrode 130. The light emitting diode canfurther include a growth substrate 110, a first insulation layer 151, asecond insulation layer 153, a first electrode pad 161, and a secondelectrode pad 163.

As for the growth substrate 110, any substrate can be used so long asthe substrate allows growth of the light emitting structure 120 thereon,and can include, for example, a sapphire substrate, a silicon carbidesubstrate, a silicon substrate, a gallium nitride substrate, an aluminumnitride substrate, and the like. In this exemplary embodiment, thegrowth substrate 110 can be a patterned sapphire substrate (PSS).

In the light emitting diode, the growth substrate 110 can be omitted.When the growth substrate 110 is used as a growth substrate for thelight emitting structure, the growth substrate 110 can be removed fromthe light emitting structure 120 using any method well-known to a personhaving ordinary knowledge in the art (hereinafter, “those skilled in theart”). The growth substrate 110 can be separated or removed from thelight emitting structure by a physical/chemical process, for example,laser lift-off, chemical lift-off, stress lift-off, polishing, and thelike.

The light emitting structure 120 can include the first conductive typesemiconductor layer 121, the active layer 123 disposed on the firstconductive type semiconductor layer 121, and the second conductive typesemiconductor layer 125 disposed on the active layer 123. Further, thelight emitting diode includes a plurality of holes 127, which are formedthrough the second conductive type semiconductor layer 125 and theactive layer 123 of the light emitting structure 120 such that the firstconductive type semiconductor layer 121 is partially exposedtherethrough.

The first conductive type semiconductor layer 121, the active layer 123and the second conductive type semiconductor layer 125 can include aIII-V-based compound semiconductor, for example, a nitride semiconductorsuch as (Al, Ga, In)N. The first conductive type semiconductor layer 121can include an n-type impurity, for example, Si, and the secondconductive type semiconductor layer 125 can include a p-type impurity,for example, Mg, or vice versa. The active layer 123 can include amulti-quantum well (MQW) structure.

The plurality of holes 127 can be formed by partially removing theactive layer 123 and the second conductive type semiconductor layer 125such that an upper surface of the first conductive type semiconductorlayer 121 is partially exposed therethrough. The number and location ofthe plural holes 127 are not particularly limited. For example, theholes 127 can be regularly arranged at constant intervals, as shown inFIG. 1. Locations of unit electrodes 131 u can be determined dependingupon the locations of the plurality of holes 127.

As described hereinafter, the first electrode 140 can form ohmic contactwith the first conductive type semiconductor layer 121 through the holes127. Thus, as the holes 127 are arranged at regular intervals in thelight emitting structure 120, the light emitting diode generally allowsuniform spreading of electric current throughout the light emittingstructure 120. Here, it should be understood that the number andlocations of holes 127 are illustrated by way of example and can bedetermined in various ways by taking into account current spreadingefficiency or current spreading performance.

Further, since the first electrode 140 forms ohmic contact with thefirst conductive type semiconductor layer 121 through the holes 127,regions of the active layer 123 to be removed to form electrodesconnected to the first conductive type semiconductor layer 121 are thesame as the regions corresponding to the plurality of holes 127. Withthis structure, the light emitting diode can minimize a region for ohmiccontact between the metal layer and the first conductive typesemiconductor layer 121, and has a higher ratio of a light emitting areato an overall chip area than light emitting diodes in the related art.

The first electrode 140 and the second electrode 130 can be electricallyconnected to the first conductive type semiconductor layer 121 and thesecond conductive type semiconductor layer 125, respectively. Forexample, the second electrode 130 can include a contact layer 131 and afirst connection layer 135, and can further include a second connectionlayer 133. On the other hand, the first electrode 140 and the secondelectrode 130 are insulated from each other. For example, the firstelectrode 140 and the second electrode 130 can be insulated from eachother by the first insulation layer 151 and the second insulation layer153.

The contact layer 131 is disposed on the second conductive typesemiconductor layer 125 and can partially cover an upper surface of thesecond conductive type semiconductor layer 125 while forming ohmiccontact therewith. In addition, the contact layer 131 can be dividedinto a plurality of unit electrodes 131 u separated from each other onthe light emitting structure 120. Here, each of the unit electrodes 131u includes an opening corresponding to at least one hole 127. Thus, atleast one hole 127 can be exposed through the opening, and the openingsof the unit electrodes 131 u can have a greater width and area than theholes 127.

The unit electrodes 131 u can be disposed on the light emittingstructure 120 so as to have substantially the same area and/or shape,and can also be regularly arranged thereon. For example, as shown inFIG. 1( a), the unit electrodes 131 u can be disposed in a latticearrangement. With the structure wherein the plural unit electrodes 131 uforming ohmic contact with the second conductive type semiconductorlayer 125 generally have the same area and/or shape, the light emittingdiode enables uniform current spreading throughout the light emittingstructure 120.

Referring again to FIG. 1( a) through FIG. 4, the unit electrodes 131 ucan be disposed based on the locations of the plurality of holes 127.For example, the opening of each of the unit electrodes 131 u can beplaced at a central portion of each of the unit electrodes 131 u, andthus each of the plural holes 127 can be placed at the central portionof each of the unit electrodes 131 u.

In operation of the light emitting diode according to the exemplaryembodiments, the first conductive type semiconductor layer 121 formsohmic contact with the first electrode 140 through the plurality ofholes 127 and the second conductive type semiconductor layer 125 formsohmic contact with each of the unit electrodes 131 u. Accordingly,electric current can be supplied to the first and second conductive typesemiconductor layers 121 and 125 through the plurality of holes 127 andthe unit electrodes 131 u, and each of the holes 127 is placed at thecentral portion of the unit electrode 131 u, whereby electric currentcan be evenly spread throughout the light emitting structure under theunit electrodes 131 u. As such, with the structure wherein the unitelectrodes 131 u and the holes 127 are evenly arranged throughout thelight emitting structure, the light emitting diode allows electriccurrent to be uniformly spread throughout the overall light emittingarea of the light emitting structure. As a result, the light emittingdiode according to the exemplary embodiment has improved currentspreading efficiency or current spreading performance.

The contact layer 131 can include a reflective metal layer, withoutbeing limited thereto. For example, the contact layer 131 can include atleast one of ITO, ZnO, IZO or Ni/Au. The contact layer 131 includingsuch a transparent conductive oxide or a transparent metal can formohmic contact with the second conductive type semiconductor layer 125.When the second electrode 130 include such a transparent conductivematerial, the second insulation layer 153 described below can be formedto exhibit reflectivity so as to act as a reflective layer.

In some embodiments, the contact layer 131 can include a reflectivelayer and a cover layer covering the reflective layer.

As described above, the contact layer 131 can form ohmic contact withthe second conductive type semiconductor layer 125 while acting as areflector reflecting light. Thus, the reflective layer can include ametal having high reflectivity and capable of forming ohmic contact withthe second conductive type semiconductor layer 125. For example, thereflective layer can include at least one of Ni, Pt, Pd, Rh, W, Ti, Al,Ag or Au. Further, the reflective layer can be composed of a singlelayer or multiple layers.

The cover layer can prevent inter-diffusion between the reflective layerand other materials, and thus can prevent damage to the reflective layerdue to diffusion of external materials into the reflective layer.Accordingly, the cover layer can be formed to cover a lower surface anda side surface of the reflective layer. The cover layer can beelectrically connected together with the reflective layer to the secondconductive type semiconductor layer 125 and thus can act as an electrodetogether with the reflective layer. The cover layer can include at leastone of, for example, Au, Ni, Ti, or Cr, and can be composed of a singlelayer or multiple layers.

Referring again to the drawings, the light emitting diode can furtherinclude the first insulation layer 151. The first insulation layer 151can partially cover the light emitting structure 120 and the contactlayer 131. In addition, the first insulation layer 151 can cover sidesurfaces of the plurality of holes 127 while exposing bottom surfaces ofthe holes 127, and can further cover a side surface of the lightemitting structure 120.

The first insulation layer 151 can include a first opening placed at aportion corresponding to the plurality of holes 127 and second openingspartially exposing the contact layer 131. The first conductive typesemiconductor layer 121 can be partially exposed through the firstopening and the holes 127, and the contact layer 131 can be partiallyexposed through the second openings. Each of the unit electrodes 131 ucan include at least one second opening.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the first insulation layer 151 can becomposed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The first electrode 140 can be disposed on the light emitting structure120 and fill the plurality of holes 127 to form ohmic contact with thefirst conductive type semiconductor layer 121. The first electrode 140can be formed to cover the entirety of the first insulation layer 151excluding some regions thereof. In some implementations, the firstelectrode 140 can be formed to cover the side surface of the lightemitting structure 120. As the first electrode 140 is formed to coverthe side surface of the light emitting structure 120, the firstelectrode 140 reflects light emitted from the active layer 123 throughthe side surface of the light emitting structure, thereby improvingluminous efficacy of the light emitting diode. The first electrode 140is not placed in regions corresponding to the second openings of thefirst insulation layer 151, and in regions virtually connecting thesecond openings. For example, as shown in FIG. 1 and FIG. 4, the firstelectrode 140 cannot be formed in regions corresponding to the secondopenings and the regions connecting the second openings.

With the structure in which the first electrode 140 is formed to coverthe entirety of the light emitting structure 120 excluding some regions,the light emitting diode can have further improved current spreadingefficiency or current spreading performance. Further, since a portion ofthe light emitting structure not covered by the contact layer 131 can becovered by the first electrode 140, the light emitting diode can havefurther improved luminous efficacy through more effective reflection oflight.

The first electrode 140 can form ohmic contact with the first conductivetype semiconductor layer 121 while acting as a reflector reflectinglight. The first electrode 140 can include at least one of Ni, Pt, Pd,Rh, W, Ti, Al, Cr, Ag or Au. For example, the first electrode 140 caninclude a highly reflective metal layer such as an Al layer. Here, thehighly reflective metal layer can be formed on a bonding layer such as aTi, Cr or Ni layer.

The first electrode 140 can be insulated from the contact layer 131 andthe side surface of the light emitting structure 121. For example, thefirst insulation layer 151 can be disposed between the first electrode140 and the contact layer 131 to be insulated therefrom.

The first connection layer 135 can electrically connect at least twosecond openings of the first insulation layer 151 to each other, wherebythe first connection layer 135 can electrically connect at least twounit electrodes 131 u to each other. Further, the light emitting diodecan further include second connection layers 133 which fill the secondopenings of the first insulation layer 151. In this structure, the firstconnection layer 135 electrically connects the unit electrodes 131 u toeach other by electrically connecting the second connection layers 133to each other.

The first connection layer 135 can be disposed on the first insulationlayer 151 and can be separated from the first electrode 140. Forexample, the first connection layer 135 can be placed in a region on thefirst insulation layer 151, in which the first electrode 140 is notplaced. For example, as shown in FIG. 1 to FIG. 4, the first connectionlayer 135 can be formed to cover a region disposed on a virtual linethat connects the second openings of one unit electrode 131 u andanother unit electrode 131 u adjacent thereto.

The first connection layer 135 can electrically connect at least twounit electrodes 131 u to each other. In some implementations, the firstconnection layer 135 can electrically connect all of the unit electrodes131 u disposed on the light emitting structure 120. For example, asshown, the first connection layer 135 can sequentially connect four unitelectrodes 131 u arranged in a vertical direction.

It should be understood that the first connection layer 135 according tothe exemplary embodiment is not limited thereto and can connect the unitelectrodes 131 u in various ways. For example, as shown in FIG. 5, thefirst connection layer 135 can sequentially connect four unit electrodes131 u arranged in the vertical direction and can be divided into aplurality of connection sections, which are disposed at differentlocations near corners of the unit electrodes 131 u such that each ofthe connection sections electrically connects only two unit electrodes131 u arranged in the vertical direction and adjacent each other. Inthis embodiment, the first connection layer 135 can electrically connectat least two second openings of the first insulation layer 151 to eachother, whereby at least two unit electrodes 131 u are electricallyconnected to each other in parallel by the first connection layer 135.With this structure, current spreading efficiency (or performance)between the plural unit electrodes 131 u can be improved, therebyimproving current spreading efficiency (or performance) of the lightemitting structure 120.

In the light emitting diode according to the exemplary embodiment, thecontact layer 131 is divided into the plurality of unit electrodes 131u, thereby providing substantially uniform luminous efficacy andintensity throughout the light emitting area. In addition, the pluralityof unit electrodes 131 u are connected to each other in parallel via thefirst connection layer 135, thereby improving current spreadingefficiency or current spreading performance throughout the lightemitting area. Accordingly, the light emitting diode can providesubstantially uniform intensity of light throughout the entirety of thechip while improving luminous efficacy.

The first connection layer 135 can be integrally formed with the secondconnection layer 133. In some implementations, the first connectionlayer 135 and the second connection layer 133 can include the samematerial as the first electrode 140. An upper surface of the firstconnection layer 135 can be substantially flush with an upper surface ofthe first electrode 140.

The second insulation layer 153 can cover the first electrode 140, thefirst connection layer 135, and the second connection layer 133. Thesecond insulation layer 153 can include third openings 153 a thatpartially expose the first electrode 140, and fourth openings 153 b thatpartially expose the first connection layer 135 or the second connectionlayer 133 disposed on the plurality of holes 127.

Each of the third and fourth openings 153 a and 153 b can be formed in asingular or plural number. In some implementations, when the thirdopening 153 a are placed near one side of the light emitting diode, thefourth opening 153 b can be placed near the other side thereof.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The light emitting diode can further include the first electrode pad 161and the second electrode pad 163.

The first electrode pad 161 can be disposed on the second insulationlayer 153 and is electrically connected to the first electrode 140through the third opening 153 a. The second electrode pad 163 can bedisposed on the second insulation layer 153 and is electricallyconnected to the first connection layer 135 and/or the second connectionlayer 133 through the fourth opening 153 b. With this structure, thefirst and second electrode pads 161 and 163 are electrically connectedto the first and second conductive type semiconductor layers 121 and125, respectively. Thus, the first and second electrode pads 161 and 163can act as electrodes through which electric power is supplied from anexternal power source to the light emitting diode.

The first electrode pad 161 and the second electrode pad 163 areseparated from each other and can include a bonding layer, such as a Ti,Cr or Ni layer, and a highly conductive layer such as an Al, Cu, Ag orAu layer. It should be understood that the present disclosure is notlimited thereto and other implementations are also possible.

FIG. 6 is a plan view of a light emitting diode according to someembodiments. The light emitting diode according to this exemplaryembodiment can further include a heat dissipation pad 170.

Referring to FIG. 6, the light emitting diode further includes the heatdissipation pad 170 disposed on the second insulation layer 153. Thelight emitting diode according to the exemplary embodiment shown in FIG.6 is generally similar to the light emitting diode shown in FIG. 1 toFIG. 4 excluding the heat dissipation pad 170.

The heat dissipation pad 170 can be formed on the second insulationlayer 153 and can be electrically insulated from the light emittingstructure 120. In some implementations, the heat dissipation pad 170 canbe disposed between the first and second electrode pads 161 and 163, andcan be electrically insulated therefrom. The heat dissipation pad 170can include a material having high thermal conductivity. For example,the heat dissipation pad 170 can include Cu.

The light emitting diode includes the heat dissipation pad 170 to alloweffective dissipation of heat generated upon light emission, whileimproving lifespan and reliability of a high output large flip-chip typelight emitting diode. Further, the light emitting diode according to theexemplary embodiment can prevent deterioration in properties thereof dueto heat generated upon light emission.

Furthermore, since the heat dissipation pad 170 is disposed on thesecond insulation layer 153 and electrically insulated from the lightemitting structure 120, it is possible to prevent electrical problems(for example, short circuit) due to the heat dissipation pad 170.

FIG. 7( a) through FIG. 12( b) are plan views and sectional viewsillustrating a method for manufacturing a light emitting diode accordingto some embodiments.

The manufacturing method according to the exemplary embodiment shown inFIG. 7( a) through FIG. 12( b) can provide the light emitting diodedescribed with reference to FIG. 1 to FIG. 4. Thus, detaileddescriptions of the same components as those of the light emitting diodeaccording to the exemplary embodiment described with reference to FIG. 1to FIG. 4 will be omitted. Thus, it should be understood that thepresent disclosure is not limited to the following exemplaryembodiments.

FIG. 7( a) through FIG. 12( b) show plan views and sectional views. Eachof the sectional views is taken along line D-D or E-E in thecorresponding plan view.

First, referring to FIGS. 7( a) and 7(b), a light emitting structure 120including a first conductive type semiconductor layer 121, an activelayer 123 and a second conductive type semiconductor layer 125 is formedon a growth substrate 110.

The growth substrate 110 can be or include a substrate which allowsgrowth of the light emitting structure 120 thereon, and can include, forexample, a patterned sapphire substrate (PSS).

The first conductive type semiconductor layer 121, the active layer 123,and the second conductive type semiconductor layer 125 are sequentiallygrown on the growth substrate 110. The light emitting structure 120 caninclude a nitride semiconductor and can be formed by a method forgrowing a nitride semiconductor layer well-known to those skilled in theart, such as MOCVD, HVPE, or MBE, and the like.

Next, referring to FIGS. 8( a) and (8(b), a plurality of holes 127 and aplurality of unit electrodes 131 u are formed by patterning the lightemitting structure 120. The plurality of holes 127 are formed to exposethe first conductive type semiconductor layer 121 and the plurality ofunit electrodes 131 u are separated from each other on the secondconductive type semiconductor layer 125 while forming ohmic contact withthe second conductive type semiconductor layer 125. Formation sequenceof the holes 127 and the unit electrodes 131 u can be freely determinedas needed.

Patterning of the light emitting structure 120 can be performed byetching and photolithography. As shown, the plurality of holes 127 canbe regularly formed, without being limited thereto.

The plurality of unit electrodes 131 u can be formed by deposition andetching of a metallic material or a transparent conductive oxide.Alternatively, the plurality of unit electrodes 131 u can be formed bydeposition and lift-off of the metallic material or the transparentconductive oxide. Each of the unit electrodes 131 u can be formed tosurround one hole 127 and can include an opening 131 a that exposes thehole 127.

The plural unit electrodes 131 u can be formed to have the holes 127placed at the center thereof and can be regularly arranged. For example,as shown, the plural unit electrodes 131 u can be disposed in a latticearrangement.

Next, referring to FIGS. 9( a) and 9(b), a first insulation layer 151can be formed to cover the light emitting structure 120 and a contactlayer 131. In addition, the first insulation layer 151 can also coverside surfaces of the plurality of holes 127.

The first insulation layer 151 can include a first opening 151 a thatexposes bottom surfaces of the plurality of holes 127, and secondopenings 151 b that partially expose the contact layer 131. The firstinsulation layer 151 can be formed by deposition and patterning of aninsulation material such as SiO₂.

Depending upon locations of the second openings 151 b of the firstinsulation layer 151, a location of a first connection layer 135 can bedetermined in a subsequent process. Accordingly, the second openings 151b can be formed at locations depending upon a desired location of thefirst connection layer 135 to be formed. For example, second openings151 b′ can be formed as shown in FIG. 9( c). When the locations of thesecond openings 151 b′ are determined as shown in FIG. 9( c), the lightemitting diode has the structure as shown in FIG. 5.

Referring to FIGS. 10( a) and 10(b), a first electrode 140 and the firstconnection layer 135 are formed on the light emitting structure 120 andthe first insulation layer 151. Furthermore, a second connection layer133 can also be formed to fill the second openings 151 b.

The first electrode 140 can be formed by deposition and patterning of ametallic material, and can be formed to cover the entirety of the firstinsulation layer 151 excluding a region in which the first connectionlayer 135 and the second connection layer 133 are formed. Further, thefirst electrode 140 can fill the first openings 151 a to form ohmiccontact with the first conductive type semiconductor layer 121 throughthe plurality of holes 127.

The second connection layer 133 can be formed to fill the secondopenings 151 b by deposition and thus is electrically connected to thecontact layer 131. The first connection layer 135 can be formed toelectrically connect at least two unit electrodes 131 u to each other.For example, the first connection layer 135 can electrically connect onesecond connection layer 133 to another second connection layer 133adjacent thereto. The first connection layer 135 can be formed on thefirst insulation layer 151. The first electrode 140, the firstconnection layer 135 and the second connection layer 133 can beseparated from each other and thus are electrically insulated from oneanother.

Further, the first electrode 140, the first connection layer 135 and thesecond connection layer 133 can be simultaneously formed by the samedeposition process. For example, the first electrode 140, the firstconnection layer 135 and the second connection layer 133 can be formedby depositing a metallic material to cover the light emitting structure120 and the first insulation layer 151, followed by patterning orlift-off the metallic material so as to form a separation region 210.Thus, the first electrode 140, the first connection layer 135 and thesecond connection layer 133 can include the same material. Further,upper surfaces of the first electrode 140, the first connection layer135 and the second connection layer 133 can be flush with each other.

As such, the first electrode 140, the first connection layer 135 and thesecond connection layer 133 are simultaneously formed by the sameprocess, thereby simplifying the process of manufacturing the lightemitting diode. It should be understood that the present disclosure isnot limited thereto and other implementations are also possible.

Although the first connection layer 135 and the second connection layer133 are formed in the form of a plurality of stripes in this exemplaryembodiment, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. Positioningand the number of first connection layers 135 connecting the pluralityof unit electrodes 131 u can be changed in various ways as needed.

Next, referring to FIGS. 11( a) and 11(b), a second insulation layer 153can be formed to cover the first electrode 140, the first connectionlayer 135 and the second connection layer 133.

The second insulation layer 153 can include at least one third opening153 a which partially exposes the first electrode 140, and at least onefourth opening 153 b which partially exposes the second connection layer133 and/or the first connection layer 135. The second insulation layer153 can be formed by deposition and patterning of an insulation materialsuch as SiO₂.

In some implementations, the second insulation layer 153 can be formedto fill a separation region 210 between the first electrode 140 and thefirst connection layer 135 or the second connection layer 133, therebyimproving electrical insulation between the first electrode 140 and thefirst connection layer 135 or the second connection layer 133.

The third opening 153 a can be formed near one side of the lightemitting diode and the fourth opening 153 b can be formed near the otherside of the light emitting diode. Thus, the third and fourth openings153 a and 153 b can be formed near opposite sides of the light emittingdiode, respectively, as shown in the drawings.

Then, a first electrode pad 161 and a second electrode pad 163 can befurther formed on the second insulation layer 153. As a result, a lightemitting diode as shown in FIG. 10( a) through FIG. 12( b) can beprovided.

The first electrode pad 161 can be formed on the third openings 153 a tofill the third openings 153 a, and thus is electrically connected to thefirst electrode 140. Similarly, the second electrode pad 163 can beformed on the fourth openings 153 b to fill the fourth openings 153 b,and thus is electrically connected to the contact layer 131. The firstelectrode pad 161 and the second electrode pad 163 can be used as padsfor connection of bumps for mounting the light emitting diode on asub-mount, a package, or a printed circuit board, or pads for surfacemount technology (SMT).

The first and second electrode pads 161 and 163 can be formedsimultaneously by the same process, for example, a photolithography andetching process or a lift-off process.

In addition, the method for manufacturing a light emitting diode canfurther include separating the growth substrate 110 from the lightemitting structure 120. The growth substrate 110 can be separated orremoved by a physical and/or chemical method.

The method for manufacturing a light emitting diode can further includeforming a heat dissipation pad 170 on the second insulation layer 153.The heat dissipation pad 170 can be formed together with the first andsecond electrode pads 161, 163 at the same time. The method formanufacturing a light emitting diode further including forming the heatdissipation pad 170 provides the light emitting diode as shown in FIG.6.

FIG. 13 is a sectional view of a light emitting device according to someembodiments. In addition, FIG. 15 is a sectional view of a lightemitting diode according to some embodiments, and FIG. 16 to FIG. 18 areplan views and sectional views of a light emitting diode according tosome embodiments.

Referring to FIG. 13, the light emitting device includes a lightemitting diode 100 and a substrate 200. The light emitting diode 100 canbe disposed on the substrate 200.

The light emitting diode 100 includes a light emitting section 100L, afirst bump 181, a second bump 183, and a heat dissipation bump 185. Thelight emitting diode 100 can further include an insulation layer 150 andan insulation material unit 190. On the other hand, the substrate 200can include a base 210 and a conductive pattern 230, and can furtherinclude an insulation pattern 220 placed in at least some region betweenthe base 210 and the conductive pattern 230.

First, the light emitting diode 100 will be described hereinafter.

The light emitting section 100L can include a light emitting structurewhich includes a first conductive type semiconductor layer, a secondconductive type semiconductor layer, and an active layer disposedbetween the first conductive type semiconductor layer and the secondconductive type semiconductor layer. As for the structure of the lightemitting section 100L, any structure allowing a first bump 181 and asecond bump 183 to be electrically connected to a lower side thereof canbe used without limitation. Details of the light emitting diode 100 andthe light emitting section 100L will be described hereinafter withreference to FIG. 15 to FIG. 18.

The first bump 181 and the second bump 183 can be disposed under thelight emitting structure 120. The first bump 181 and the second bump 183are separated from each other to be insulated from each other, and canbe electrically connected to different polarities. For example, thefirst bump 181 can be electrically connected to an N-type semiconductorlayer of the light emitting section 100L, and the second bump 183 can beelectrically connected to a P-type semiconductor layer of the lightemitting section 100L.

The first bump 181 can be placed near one side of a lower surface of thelight emitting section 100L and the second bump 183 can be placed nearthe other side of the lower surface of the light emitting section 100L.In this structure, a certain space can be defined between the first bump181 and the second bump 183, as shown in the drawings. The heatdissipation bump 185 can be disposed in this space. Accordingly, theheat dissipation bump 185 can be disposed between the first bump 181 andthe second bump 183. However, it should be understood that the presentdisclosure is not limited thereto and other implementations are alsopossible. Arrangement of the first and second bumps 181 and 183 and theheat dissipation bump 185 can be changed in various ways as needed.

The first bump 181 and the second bump 183 can include a conductivematerial, such as metal, and particularly, a solder. The solder can beor include a typical solder known to those skilled in the art and caninclude Sn, Cu, Ag, Bi, In, Zn, Sb, or Pb, and the like. For example,the solder can be or include a Sn—Ag—Cu-based solder.

In addition, each of the first bump 181 and the second bump 183 can becomposed of a single layer or multiple layers. When each of the firstbump 181 and the second bump 183 is composed of a single layer, thefirst bump 181 and the second bump 183 can be composed of or includesolders. Alternatively, when each of the first bump 181 and the secondbump 183 is composed of multiple layers, a solder layer can be placed atthe lowermost layer. Here, the solder layer can contact the conductivepattern 230 of the substrate 200 to be bonded thereto.

The heat dissipation bump 185 can be disposed under the light emittingsection 100L and can be electrically connected to the light emittingsection 100L. The heat dissipation bump 185 can serve to dissipate heatfrom the light emitting section 100L to the outside of the lightemitting section 100L.

The heat dissipation bump 185 can include a material having a relativelyhigh thermal conductivity. In some implementations, the thermalconductivity of the heat dissipation bump 185 can be higher than thoseof the first and second bumps 181 and 183. The heat dissipation bump 185can include a metal and can also include solders. The solder can be orinclude a typical solder known to those skilled in the art and includeSn, Cu, Ag, Bi, In, Zn, Sb, or Pb, and the like. For example, the soldercan be or include a Sn—Ag—Cu-based solder, without being limitedthereto. For example, the solder of the heat dissipation bump 185 canhave higher thermal conductivity than the first bump 181 and the secondbump 183.

In addition, the heat dissipation bump 185 can be composed of a singlelayer or multiple layers. When the heat dissipation bump 185 is composedof multiple layers, a solder layer can be disposed at the lowermostside. The solder layer can contact the base 210 of the substrate 200 tobe bonded thereto.

Since the heat dissipation bump 185 is physically connected to the lightemitting section 100L, heat dissipation efficiency of the light emittingdiode can increase with increasing area of the heat dissipation bump185. Thus, a contact area between the heat dissipation bump 185 and thelight emitting section 100L can be greater than the contact area betweenthe first bump 181 and/or the second bump 183 and the light emittingsection 100L. Further, since the thermal conductivity of the heatdissipation bump 185 can be higher than those of the first and secondbumps 181 and 183, the light emitting device can have further improvedheat dissipation efficiency. In addition, the heat dissipation bump 185can be disposed between the first bump 181 and the second bump 183 to bedisposed under a central portion of the light emitting section 100L.However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. Arrangementof the heat dissipation bump 185, the first bump 181 and the second bump183 can be changed in various ways as needed.

The light emitting diode 100 can further include the insulation layer150, which insulates the light emitting section 100L from the heatdissipation bump 185. The insulation layer 150 can include asilicon-based insulation material such as SiO_(x), or SiN_(x), and thelike, and can also include another insulation material having goodthermal conductivity. Further, the insulation layer can include adistributed Bragg reflector in which materials having different indexesof refraction are alternately stacked one above another.

As such, since the heat dissipation bump 185 is insulated from the lightemitting section 100L by the insulation layer 150, it is possible tominimize electrical problems such as short circuit by the heatdissipation bump 185 during operation of the light emitting device. Atthe same time, the heat dissipation bump 185 is physically connected tothe light emitting section 100L with the insulation layer 150 interposedtherebetween, so that heat generated in the light emitting section 100Lcan be effectively transferred to the heat dissipation bump 185, therebyimproving heat dissipation efficiency of the light emitting diode 100.

As described above, according to the exemplary embodiment, the firstbump 181, the second bump 183 and the heat dissipation bump 185 includethe solders. Accordingly, in a process of mounting the light emittingdiode 100 on the substrate 200, the light emitting diode 100 can bebonded to the substrate 200 simply by placing the light emitting diode100 in a certain region of the substrate 200, followed by heating to amelting point of the solder and cooling.

Specifically, the method for manufacturing the light emitting deviceaccording to some embodiments will be described with reference to FIG.14.

Referring to FIG. 14, the light emitting diode 100 is disposed on thesubstrate 200 which includes the base 210 and the conductive pattern230. The light emitting diode 100 can be placed at a locationcorresponding to a protrusion of the base 210. The protrusion of thebase 210 can serve to indicate a mounting region of the light emittingdiode 100. Thus, a process of mounting the light emitting diode 100 canbe easily performed.

Then, as the temperature is increased to the melting point of the solderand is then decreased, the solders included in the first bump 181, thesecond bump 183 and heat dissipation bump 185 are dissolved and thencooled to bond the light emitting diode 100 to the substrate 200. Forexample, when the insulation material unit 190 is formed, the first bump181, the second bump 183 and the heat dissipation bump 185 are preventedfrom flowing to a side surface or from being deformed, thereby improvingprocess reliability.

As such, according to the exemplary embodiment, a separate component forbonding the light emitting diode 100 to the substrate 200 can beomitted. For example, there is no need for additional provision of asolder or a bonding agent between the light emitting diode 100 and thesubstrate 200 for bonding. Accordingly, it is possible to minimizeelectrical problems such as short circuit upon the soldering process,and the process of mounting the light emitting diode 100 on thesubstrate 200 can be very conveniently performed. In addition, themanufacturing method according to the exemplary embodiment can preventfailure caused by the bonding process such as soldering, therebyimproving reliability of the light emitting device.

Referring again to FIG. 13, the light emitting diode 100 can furtherinclude an insulation material unit 190 surrounding side surfaces of thefirst bump 181, the second bump 183 and the heat dissipation bump 185.

The insulation material unit 190 exhibits electrical insulationproperties and covers the side surface of the first bump 181, the secondbump 183 and the heat dissipation bump 185 such that the first bump 181,the second bump 183 and the heat dissipation bump 185 can be effectivelyinsulated from one another. Further, the insulation material unit 190can also serve to support the first bump 181, the second bump 183 andthe heat dissipation bump 185. Accordingly, it is possible to preventthe solders in the first bump 181, the second bump 183 and the heatdissipation bump 185 from being fused and bonded to each other in theprocess of mounting the light emitting diode 100 on the substrate 200.

A lower surface of the insulation material unit 190 can be generallyflush with lower surfaces of the first bump 181, the second bump 183 andthe heat dissipation bump 185. With this structure, the light emittingdiode 100 can be more stably mounted on the substrate 200.

The insulation material unit 190 can include a resin. The resin caninclude Si or other polymer materials. Further, the insulation materialunit 190 can exhibit optical reflectivity, and when the insulationmaterial unit 190 includes a resin, the resin can include a resin, suchas Si, which can reflect light. Alternatively, the resin can includelight reflecting and scattering particles such as TiO₂ particles. As theinsulation material unit 190 exhibits light reflectivity, light emittedfrom the light emitting section 100L is reflected upwards, therebyimproving luminous efficacy of the light emitting device.

In addition, the insulation material unit 190 can further cover a sidesurface of the light emitting section 100L, whereby a light emittingangle of the light emitting diode 100 can be changed. For example, whenthe insulation material unit 190 further covers the side surface of thelight emitting section 100L, some of light emitted through the sidesurface of the light emitting diode 100 can be reflected upwards. Thus,when the insulation material unit 190 is formed on the side surface ofthe light emitting section 100L, the ratio of light traveling to anupper portion of the light emitting diode 100 is increased. In this way,the light emitting angle of the light emitting diode 100 can be adjustedby regulating a region in which the insulation material unit 190 isplaced.

The substrate 200 includes the base 210 and the conductive pattern 230,and can further include an insulation pattern 220.

The base 210 can act as a supporter of the substrate 200, andparticularly include a material having good thermal conductivity. Forexample, the base 210 can include a metallic material having goodthermal conductivity, such as Ag, Cu, Au, Al, or Mo, and the like. Inaddition, the base 210 can be composed of a single layer or multiplelayers. Alternatively, the base 210 can include a ceramic material orpolymer material having good thermal conductivity.

Further, the base 210 can directly contact the heat dissipation bump185. In addition, the base 210 can include a protrusion, which contactsthe heat dissipation bump 185 of the light emitting diode 100. An uppersurface of the protrusion can be generally flush with an upper surfaceof the conductive pattern 230. Accordingly, when the light emittingdiode 100 is mounted on the substrate 200, stable contact between thebase 210 and the heat dissipation bump 185 can be secured.

With the structure wherein the heat dissipation bump 185 directlycontacts the base 210 including a material having good thermalconductivity, the light emitting device can effectively transfer heatfrom the light emitting diode 100 to the base 210 upon operation of thelight emitting diode. Accordingly, the light emitting device hasimproved heat dissipation efficiency.

According to the exemplary embodiment, the heat dissipation bump 185physically connected to the light emitting section 100L is physicallyconnected to the base 210 of the substrate 200, thereby enablingeffective dissipation of heat upon light emission. Thus, it is possibleto solve a problem of deterioration in thermal conductivity between thebase of the substrate and the light emitting diode in the related art.

The conductive pattern 230 can be disposed on the base 210 while beinginsulated from the base 210. The conductive pattern 230 can beelectrically connected to the first and second bumps 181 and 183. Thus,the conductive pattern 230 can include a first conductive patternelectrically connected to the first bump 181 and a second conductivepattern electrically connected to the second bump 183. Here, the firstand second conductive patterns can be insulated from each other. Asshown in the drawings, the first bump 181 and the second bump 183 can bedisposed on the conductive pattern 230 and electrically connected toeach other.

When the base 210 includes a material having electrical conductivitysuch as a metal, an insulation pattern 220 can be disposed between thebase 210 and the conductive pattern 230 to insulate the base 210 fromthe conductive pattern 230. In addition, when the base 210 includes theprotrusion, the conductive pattern 230 can be separated from theprotrusion to be insulated therefrom. Further, an insulation material(not shown) can be interposed between the protrusion of the base 210 andthe conductive pattern 230.

Alternatively, when the base 210 includes a ceramic material or apolymer material to exhibit electrical insulation properties, theinsulation pattern 220 can be omitted.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. Theconductive pattern 230 can be formed in plural numbers. The conductivepattern 230 can have various shapes depending upon the number and shapesof bumps of the light emitting diode 100. The conductive pattern 230 canact as an electrical circuit or a lead of the light emitting device.

On the other hand, the conductive pattern 230 can be placed at alocation corresponding to the first and second bumps 181 and 183, andthe protrusion of the base 210 can be placed at a location correspondingto the heat dissipation bump 185. Furthermore, an upper surface of theconductive pattern 230 can be generally flush with an upper surface ofthe protrusion. With this structure, the light emitting diode 100 can bestably mounted on an upper surface of the substrate 200. The conductivepattern 230 can include, for example, a metal.

According to some embodiments, the substrate 200 has a structure whereinthe insulation pattern 220 and the conductive pattern 230 are formed onthe base 210. Accordingly, a typical process of patterning an insulationlayer between bases can be omitted, thereby reducing manufacturing costsof the light emitting device. In addition, the base 210 includes theprotrusion, which directly contacts the heat dissipation bump 185 of thelight emitting diode 100, whereby a contact area between the base 210and the light emitting diode 100 increases, thereby significantlyimproving heat dissipation efficiency.

On the other hand, although a single light emitting diode 100 is mountedon the substrate 200 in this exemplary embodiment, the presentdisclosure is not limited thereto and other implementations are alsopossible. The light emitting device according to exemplary embodimentscan include a plurality of light emitting diodes 100 mounted on thesubstrate 200. The plurality of light emitting diodes 100 can beelectrically connected to each other in series, in parallel, or inreverse parallel. Electrical connection between the plurality of lightemitting diodes 100 can be achieved by the conductive pattern 230. Here,the conductive pattern 230 can act as an electrical circuit.

As described above, the light emitting device according to the exemplaryembodiments of the disclosure can include various forms of lightemitting diodes. First, FIG. 15 is a sectional view of a light emittingdiode according to some embodiments. In the exemplary embodiment shownin FIG. 15, detailed descriptions of components having the samereference numerals as those of the embodiment shown in FIG. 13 will beomitted.

Referring to FIG. 15, the light emitting diode 100 a according to thisexemplary embodiment can be or include a flip-chip type light emittingdiode. The light emitting diode 100 a includes a light emittingstructure 120, a first bump 181, a second bump 183 and a heatdissipation bump 185, and can further include a first electrode pad 141,a second electrode pad 131, and an insulation layer 150′.

The light emitting structure 120 can include a first conductive typesemiconductor layer 121, a second conductive type semiconductor layer125, and an active layer 123 disposed between the first conductive typesemiconductor layer 121 and the second conductive type semiconductorlayer 125. The light emitting structure 120 can include mesas includingthe second conductive type semiconductor layer 125 and the active layer123, and the first conductive type semiconductor layer 121 can bepartially exposed in a region in which the mesas are not formed.

The first electrode pad 141 can be disposed on an exposed region of thefirst conductive type semiconductor layer 121 between the first bump 181and the first conductive type semiconductor layer 121. Similarly, thesecond electrode pad 143 is disposed on the second conductive typesemiconductor layer 125 between the second bump 183 and the secondconductive type semiconductor layer 125. The first electrode pad 141 andthe second electrode pad 143 can form ohmic contact with the firstconductive type semiconductor layer 121 and the second conductive typesemiconductor layer 125, respectively.

In addition, the light emitting diode 100 a can further include aninsulation layer 150′ disposed between the light emitting structure 120and the heat dissipation bump 185. Further, the insulation layer 150′can cover a lower surface of the light emitting structure 120 and sidesurfaces of the first electrode pad 141 and the second electrode pad 143to protect the light emitting structure 120 from the outside. Theinsulation layer 150′ can include a similar material to that of theinsulation layer 150 according to the exemplary embodiment of FIG. 13.

On the other hand, although FIG. 15 shows that the growth substrate isseparated from the light emitting diode 100 a, the light emitting diode100 a can further include a growth substrate disposed on the firstconductive type semiconductor layer 121. Here, as for the growthsubstrate, any substrate can be used without limitation so long as thesubstrate allows growth of the light emitting structure 120 thereon. Forexample, the growth substrate can include a sapphire substrate, asilicon carbide substrate, a silicon substrate, a gallium nitridesubstrate, or an aluminum nitride substrate, and the like.

As shown in FIG. 15, the first bump 181, the second bump 183 and theheat dissipation bump 185 are formed under the light emitting structure120 of the flip-chip type light emitting diode 100 a, thereby providinga light emitting diode having improved heat dissipation efficiencywithout changing the structure of a typical flip-chip type lightemitting diode. Further, the light emitting diode 100 a of FIG. 15 canbe mounted on the substrate 200, thereby providing a light emittingdiode having improved heat dissipation efficiency.

FIG. 16( a) through FIG. 18 are plan views and sectional views of alight emitting diode according to some embodiments. FIG. 16 (a) is aplan view illustrating locations of plural holes 127 a and a connectionstructure 127 b, and FIG. 16 (b) is a plan view illustrating a lowersurface of a light emitting diode 100 b. FIG. 17 and FIG. 18 aresectional views taken along lines F-F and G-T in FIGS. 16( a) and 16(b).

Referring to FIG. 16( a) through FIG. 18, the light emitting diode 100 bincludes a light emitting structure 120 which includes a firstconductive type semiconductor layer 121, an active layer 123 and asecond conductive type semiconductor layer 125, a second electrode 130,a first electrode 140, a first insulation layer 151, a first bump 181, asecond bump 183, and a heat dissipation bump 185. In someimplementations, the light emitting diode 100 b can further include asecond insulation layer 153 and an insulation material unit 190.

The light emitting structure 120 includes the first conductive typesemiconductor layer 121, the active layer 123 disposed on the firstconductive type semiconductor layer 121, and the second conductive typesemiconductor layer 125 disposed on the active layer 123. Further, thelight emitting structure 120 can include a plurality of holes 127 aformed through the second conductive type semiconductor layer 125 andthe active layer 123 such that the first conductive type semiconductorlayer 121 is partially exposed therethrough, and can further include atleast one connection structure 127 b connecting the plurality of holes127 a to each other.

The plurality of holes 127 a can be formed by partially removing theactive layer 123 and the second conductive type semiconductor layer 125such that an upper surface of the first conductive type semiconductorlayer 121 is partially exposed therethrough. The number and location ofthe plural holes 127 a are not particularly limited. For example, asshown in the drawings, the plurality of holes 127 a can be arrangedthroughout the entirety of the light emitting structure 120.

In addition, the plurality of holes 127 a can be connected to each otherby the at least one connection structure 127 b, which is formed bypartially removing the active layer 123 and the second conductive typesemiconductor layer 125 such that the upper surface of the firstconductive type semiconductor layer 121 is partially exposedtherethrough. For example, as shown in FIG. 16, the plurality of holes127 a can be connected by the at least one connection structure 127 b.For example, all of the holes 127 a can be connected.

As described below, the first electrode 140 can form ohmic contact withthe first conductive type semiconductor layer 121 through the holes 127a. Accordingly, the plural holes 127 a are disposed throughout the lightemitting structure 120, thereby allowing substantially uniform currentspreading throughout the light emitting structure 120. In addition, theplurality of holes 127 a are connected by the connection structure 127b, whereby electric current can be substantially uniformly spreadthroughout the light emitting structure 120 instead of crowding at acertain hole 127 a.

The light emitting structure 120 can include a roughness R on an uppersurface thereof. The roughness R can be formed by dry etching and/or wetetching. For example, the roughness R can be formed by wet etching theupper surface of the light emitting structure 120 using a solutionincluding at least one of KOH or NaOH, or by PEC etching. In someimplementations, the roughness R can be formed by combination of wetetching and dry etching. It should be understood that these method forforming the roughness R are provided for illustration only, and theroughness R can be formed on the surface of the light emitting structure120 using various methods known to those skilled in the art. The lightemitting diode 100 b can have improved light extraction efficiency byforming the roughness R on the surface of the light emitting structure120.

Further, since the first electrode 140 forms ohmic contact with thefirst conductive type semiconductor layer 121 through the holes 127 a,regions of the active layer 123 removed to form electrodes connected tothe first conductive type semiconductor layer 121 are the same as theregions of the plurality of holes 127 a. This structure can minimize anarea of the first conductive type semiconductor layer 121 for ohmiccontact with the metal layer, thereby providing a light emitting diodehaving a relatively large area ratio of light emitting area to ahorizontal area of the overall light emitting structure.

The second electrode 130 is disposed on the second conductive typesemiconductor layer 125. The second electrode 130 can partially cover alower surface of the second conductive type semiconductor layer 125while forming ohmic contact therewith. Further, the second electrode 130can be disposed to cover the lower surface of the second conductive typesemiconductor layer 125 and can be formed as a monolithic layer. In someimplementations, the second electrode 130 can be formed to cover theremaining region of the lower surface of the second conductive typesemiconductor layer 125 excluding the regions in which the plurality ofholes 127 a and the connection structure 127 b are formed. With thisstructure, the light emitting diode can uniformly supply electriccurrent to the entirety of the light emitting structure 120, therebyimproving current spreading efficiency or current spreading performance.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. The secondelectrode 130 can be formed as a plurality of unit electrode layersdisposed on the lower surface of the second conductive typesemiconductor layer 125 instead of being formed as a monolithic layer.The second electrode 130 can include a reflective layer and a coverlayer covering the reflective layer. The second electrode 130 accordingto this exemplary embodiment is generally similar to the secondelectrode according to the aforementioned exemplary embodiments, and adetailed description thereof will be omitted.

On the other hand, the light emitting diode 100 b can further include afirst insulation layer 151. The first insulation layer 151 can partiallycover a lower surface of the light emitting structure 120 and the secondelectrode 130. In some implementations, the first insulation layer 151can partially fill the connection structure 127 b to be interposedbetween the first conductive type semiconductor layer 121 exposedthrough the connection structure 127 b and the first electrode 140, andto be disposed in a region between the second electrode 130 and thefirst electrode 140, which excludes the plurality of holes 127 a. Inaddition, the first insulation layer 151 covers side surfaces of theplurality of holes 127 a while exposing upper surfaces of the holes 127a to partially expose the first conductive type semiconductor layer 121.Furthermore, the first insulation layer 151 can also cover a sidesurface of the light emitting structure 120.

The first insulation layer 151 can include a first opening 151 a placedat a portion corresponding to the plurality of holes 127 a and secondopenings 151 b that partially expose the second electrode 130. The firstconductive type semiconductor layer 121 can be partially exposed throughthe first opening 151 a and the holes 127 a, and the second electrode130 can be partially exposed through the second openings 151 b.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the first insulation layer 151 can becomposed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The first electrode 140 can be disposed on the lower surface of thelight emitting structure 120 and can fill the plurality of holes 127 aand/or the first opening 151 a to form ohmic contact with the firstconductive type semiconductor layer 121. The first electrode 140 can beformed to cover the entirety of the first insulation layer 151 excludingsome regions of the lower surface of the first insulation layer 151.Alternatively, although not shown in the drawings, the first electrode140 can be formed to cover the side surface of the light emittingstructure 120. When first electrode 140 is formed to cover the sidesurface of the light emitting structure 120, the first electrode 140reflects light emitted through the side surface of the light emittingstructure from the active layer 123 in an upward direction, therebyincreasing a ratio of light emitted through the upper surface of thelight emitting diode 100 b. On the other hand, the first electrode 140is not placed in a region corresponding to the second openings 151 b ofthe first insulation layer 151, and is insulated from the reflectivemetal layer 130.

The first electrode 140 is formed to cover the overall lower surface ofthe light emitting structure 120 excluding some regions, thereby furtherimproving current spreading efficiency or current spreading performance.In addition, since a portion of the light emitting structure 120 notcovered by the second electrode 130 can be covered by the firstelectrode 140, light can be more effectively reflected, therebyimproving luminous efficacy of the light emitting diode 100 b. The firstelectrode 140 can form ohmic contact with the first conductive typesemiconductor layer 121 while acting as a reflector reflecting light.

The light emitting diode 100 b can further include the second insulationlayer 153. The second insulation layer 153 can cover the first electrode140. The second insulation layer 153 can include third openings 153 athat partially expose the first electrode 140, and fourth openings 153 bthat partially expose the second electrode 130. Here, the fourthopenings 153 b can be formed at locations corresponding to the secondopenings 151 b.

Each of the third and fourth openings 153 a and 153 b can be formed in asingular or plural numbers. In addition, when the third openings 153 aare placed near one side of the light emitting diode, the fourthopenings 153 b can be placed near the other side thereof.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The first bump 181 can be disposed on a lower surface of the secondinsulation layer 153 and is electrically connected to the firstelectrode 140 through the third openings 153 a. The second bump 183 canbe disposed on the lower surface of the second insulation layer 153 andis electrically connected to the second electrode 130 through the fourthopenings 153 b. Accordingly, the first and second bumps 181 and 183 areelectrically connected to the first and second conductive typesemiconductor layers 121, 125, respectively. Accordingly, the first andsecond bumps 181, 183 can act as electrodes through which electric poweris supplied from an external power source to the light emitting diode.

The heat dissipation bump 185 can be disposed on the lower surface ofthe second insulation layer 153 and can be disposed under the lightemitting structure 120. The heat dissipation bump 185 can be physicallyconnected to the light emitting structure 120 to dissipate heat from thelight emitting structure 120 to the outside. Further, the heatdissipation bump 185 can be disposed between the first bump 181 and thesecond bump 183 to be disposed under a central portion of the lightemitting structure 120. However, it should be understood that thepresent disclosure is not limited thereto and other implementations arealso possible. Arrangement of the heat dissipation bump 185, the firstbump 181 and the second bump 183 can be changed in various ways asneeded.

In addition, as in the embodiment shown in FIG. 13, the first and secondbumps 181 and 183 and the heat dissipation bump 185 can include solders.

According to some embodiments, a light emitting device including thelight emitting diode 100 b according to the exemplary embodiment of FIG.16 to FIG. 18 can be provided. According to this exemplary embodiment,the light emitting diode 100 b has high current spreading efficiency orcurrent spreading performance to allow application of high electriccurrent while securing high heat dissipation efficiency even uponapplication of high electric current. Accordingly, the structure of thelight emitting diode according to this exemplary embodiment is verysuitable for a high output light emitting device.

FIG. 19( a) to FIG. 24( b) are plan views and sectional views of a lightemitting diode chip and a method for manufacturing the same according tosome embodiments. Specifically, the light emitting diode chip of FIGS.24( a) and 24(b) can be manufactured by the manufacturing methoddescribed with reference to FIG. 19( a) through FIG. 24( b). In each ofthe drawings, (a) shows a plan view and (b) shows a sectional view takenalong line H-H in the plan view.

Referring to FIGS. 19( a) and 19(b), a light emitting structure 120including a first conductive type semiconductor layer 121, an activelayer 123, and a second conductive type semiconductor layer 125 isformed on a growth substrate 110.

As for the growth substrate 110, any substrate can be used so long asthe substrate allows growth of the light emitting structure 120 thereon,and can include, for example, a sapphire substrate, a silicon carbidesubstrate, a silicon substrate, a gallium nitride substrate, an aluminumnitride substrate, and the like. In this exemplary embodiment, thegrowth substrate 110 can be a patterned sapphire substrate (PSS).

The light emitting structure 120 can be formed by sequentially growingthe first conductive type semiconductor layer 121, the active layer 123,and the second conductive type semiconductor layer 125. The lightemitting structure 120 can include a nitride semiconductor and can beformed by a method for growing a nitride semiconductor layer well-knownto those skilled in the art, such as MOCVD, HYPE, or MBE, and the like.In addition, before growth of the first conductive type semiconductorlayer 121, a buffer layer (not shown) can be further formed on thegrowth substrate 110. The first conductive type semiconductor layer 121and the second conductive type semiconductor layer 125 can havedifferent polarities. For example, the first conductive typesemiconductor layer 121 can be doped with n-type impurities includingSi, and the second conductive type semiconductor layer 125 can be dopedwith n-type impurities including Mg.

Next, referring to FIGS. 20( a) and 20(b), mesas M1 and M2 including theactive layer 123 and the second conductive type semiconductor layer 125are formed by patterning the light emitting structure 120, and a secondelectrode 130 is formed on the mesas M1 and M2. It should be noted thatthere is no sequential relationship between patterning of the lightemitting structure 120 and formation of the second electrode 130.

Patterning of the light emitting structure 120 can include partiallyremoving the light emitting structure 120 by, for example,photolithography and etching. The mesas M1 and M2 can be formed bypatterning the light emitting structure 120, and can be formed to haveinclined side surfaces using photoresist reflow technology. The inclinedprofile of the side surfaces of the mesas M1 and M2 improves extractionefficiency of light emitted from the active layer 123.

The mesas M1 and M2 can include a first mesa M1 and a second mesa M2,and in order to form the mesas M1 and M2, a partially exposed region 120a of the first conductive type semiconductor layer 121 can be formed inwhich the light emitting structure 120 is partially removed.

The first mesa M1 and the second mesa M2 can be separated from eachother and the second mesa M2 can be formed to be surrounded by the firstmesa M1. With this structure, the second mesa M2 can be placed at acentral portion of the light emitting diode chip. As shown in thedrawing, the first mesa M1 can be or include a monolithic mesa. Theexposed region 120 a of the first conductive type semiconductor layer121 can be formed around the first mesa M1, and the shape of the firstmesa M1 can be determined depending upon the shape of the exposed region120 a. For example, as shown in the drawings, the exposed region 120 aof the first conductive type semiconductor layer 121 can be formed alonga periphery of the light emitting diode chip, and can also be placed ata portion extending from the periphery of the light emitting diode chiptowards the second mesa M2.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. The firstmesa M1 can include a plurality of mesas and the exposed region 120 a ofthe first conductive type semiconductor layer 121 can be modified invarious ways. Further, as described below, the first mesa M1 cancorrespond to a light emitting area of a light emitting diode region LRand the second mesa M2 can correspond to a region of a protective dioderegion PR. Thus, the first mesa M1 can be modified in various waysaccording to a light emitting area to be defined.

The second electrode 130 is formed on the mesas M1 and M2 and covers atleast part of an upper surface of the second conductive typesemiconductor layer 125 to form ohmic contact with the second conductivetype semiconductor layer 125. For example, the second electrode 130 cancover most of the upper surface of the second conductive typesemiconductor layer 125, thereby improving current spreading efficiencyor current spreading performance in the second conductive typesemiconductor layer 125.

The second electrode 130 can form ohmic contact with the secondconductive type semiconductor layer 125. Accordingly, the secondelectrode 130 can include a material capable of forming ohmic contactwith a second conductive type nitride semiconductor layer. For example,when the second conductive type is a p-type, the second electrode 130can include a conductive material capable of forming ohmic contact witha p-type nitride semiconductor layer. For example, the second electrode130 can include a metal or a conductive oxide.

In some implementations, the second electrode 130 can include a metalcapable of reflecting light. In this case, the, second electrode 130 caninclude a reflective layer (not shown) and a cover layer covering thereflective layer. The reflective layer and the cover layer can be formedby plating, deposition, and the like, and can be formed at a desiredlocation by patterning or lift-off. In addition, the reflective layerand cover layer can be composed of a single layer or multiple layers.Alternatively, the second electrode 130 can include a transparentconductive material. When the second electrode 130 includes atransparent conductive material, the second insulation layer 153described below can be formed to exhibit reflective characteristics,thereby providing a reflecting function.

Referring to FIGS. 21( a) and 21(b), an isolation process can beperformed to isolate the light emitting structure 120 into severalregions. The isolation process can include removing a portion of thefirst conductive type semiconductor layer 121 under the exposed region120 a to form isolated regions 120 b and 120 c.

The isolation process can be performed by photolithography and etching.By the isolation process, the first conductive type semiconductor layer121 around the mesas M1 and M2 is partially removed to form the isolatedregions 120 b and 120 c, whereby the light emitting structure can beisolated into the semiconductor structure 120 including the first mesaM1 and the semiconductor structure 120 including the second mesa M2. Forexample, the light emitting structure 120 can be divided into at leasttwo sections by the isolated region 120 b. Here, the semiconductorstructure 120 including the first mesa M1 is defined as the lightemitting diode region LR, and the semiconductor structure 120 includingthe second mesa M2 is defined as the protective diode region PR. Inaddition, the light emitting diode region LR and the protective dioderegion PR are separated from each other.

The protective diode region PR can be placed at a central portion of thegrowth substrate 110, and thus, the light emitting diode region LR canbe disposed to surround the protective diode region PR.

On the other hand, each of the light emitting diode region LR and theprotective diode region PR can include an exposed region of the firstconductive type semiconductor layer 121 in which the first mesa M1 andthe second mesa M2 are not formed. For example, in the light emittingdiode region LR, the exposed region of the first conductive typesemiconductor layer 121 can be disposed to surround the first mesa M1.

Next, referring to FIGS. 22( a) and 22(b), a first insulation layer 151can be formed. The first insulation layer 151 covers at least part ofthe light emitting diode region LR, the protective diode region PR andthe second electrode 130, and includes first and third openings 151 aand 151 c and second and fourth openings 151 b and 151 d.

The first insulation layer 151 can be formed over the entirety of thelight emitting structure excluding the regions of the openings 151 a to151 d. Here, the first and third openings 151 a and 151 c partiallyexpose an upper surface of the first conductive type semiconductor layer121, and the second and fourth openings 151 b and 151 d partially exposean upper surface of the second electrode 130.

In some implementations, the first opening 151 a can expose the firstconductive type semiconductor layer 121 of the light emitting dioderegion LR, and can be formed along an outer periphery of the lightemitting diode chip to surround the first mesa M1. In addition, thefirst opening 151 a can also be formed at a portion extending from theouter periphery of the light emitting diode chip towards the protectivediode region PR side. On the other hand, the third opening 151 c can atleast partially expose the first conductive type semiconductor layer 121of the protective diode region PR.

The second opening 151 b can expose the second electrode 130 of theprotective diode region PR. Here, the second opening 151 b can bedisposed biased towards one side of the light emitting diode chip, asshown in the drawing. On the other hand, the fourth opening 151 d can atleast partially expose the second electrode 130 of the light emittingdiode region LR. Here, the third opening 151 c can be disposed betweenthe second opening 151 b and the fourth opening 151 d.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). In addition, the first insulation layer 151can be composed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another. Particularly, when the secondelectrode 130 includes a transparent conductive material, the firstinsulation layer 151 can include a reflective material or thedistributed Bragg reflector. With this structure, the first insulationlayer 151 can improve luminous efficacy of the light emitting diodewhile acting as a reflector that reflects light. The first insulationlayer 151 can be formed by various methods depending upon formationmaterials. For example, the first insulation layer 151 can be formed bydeposition.

Next, referring to FIGS. 23( a) and 23(b), a first electrode 140 and aconnection electrode 145 are formed on the first insulation layer 151 tocover the first insulation layer 151. Here, the first electrode 140 isseparated from the connection electrode 145 and a separation region 140a can be formed therebetween.

The first electrode 140 can be formed to cover a substantially overallupper surface of the first insulation layer 151, and can fill the firstopening 151 a and the fourth opening 151 d. The first electrode 140 canbe insulated from the second electrode 130 and the first conductive typesemiconductor layer 121 of the protective diode region PR, and thus isnot formed at locations of the second opening 151 b and the thirdopening 151 c. With this structure, the first electrode 140 can beelectrically connected to the first conductive type semiconductor layer121 of the light emitting diode region LR through the first opening 151a, and can form ohmic contact with the first conductive typesemiconductor layer 121. Further, the first electrode 140 can beelectrically connected to the second electrode 130 of the protectivediode region PR through the fourth opening 151 d. Accordingly, the firstconductive type semiconductor layer 121 of the light emitting dioderegion LR is electrically connected to the second conductive typesemiconductor layer 125 of the protective diode region PR through thefirst electrode 140.

The connection electrode 145 is separated from the first electrode 140and can be formed in a region in which the first electrode 140 is notformed. For example, the connection electrode 145 can be formed in aregion, in which the first electrode 140 is not formed and the secondand third openings 151 b and 151 c are placed, whereby the second andthird openings 151 b and 151 c can be filled with the connectionelectrode 145. With this structure, the connection electrode 145 can beelectrically connected to the second electrode 130 of the light emittingdiode region LR through the second openings 151 b, and electricallyconnected to the first conductive type semiconductor layer 121 of theprotective diode region PR through the third opening 151 c, and can formohmic contact with the first conductive type semiconductor layer 121.Accordingly, the second electrode 130 of the light emitting diode regionLR and the first conductive type semiconductor layer 121 of theprotective diode region PR are electrically connected to each otherthrough the connection electrode 145.

As described above, the first and second conductive type semiconductorlayers 121 and 125 of the light emitting diode region LR areelectrically connected to the second and first conductive typesemiconductor layers 125 and 121 of the protective diode region PR,respectively. Accordingly, the light emitting diode region LR and theprotective diode region PR are connected to each other in reverseparallel. Accordingly, in operation of the light emitting diode chipaccording to the exemplary embodiment, the protective diode region PRcan perform a similar function to that of a Zener diode connected to thelight emitting diode region LR in reverse parallel, thereby preventingdamage or failure of the light emitting diode region LR due toelectrostatic discharge.

On the other hand, the first electrode 140 and the connection electrode145 can include a metallic material capable of forming ohmic contactwith a nitride semiconductor and can have high reflectivity. The firstelectrode 140 and the connection electrode 145 including a metallicmaterial can be formed on the first insulation layer 151 by plating ordeposition. Further, the first electrode 140 and the connectionelectrode 145 can be formed at the same time and can include the samematerial. However, it should be understood that the present disclosureis not limited thereto and other implementations are also possible.

Next, referring to FIGS. 24( a) and 24(b), a second insulation layer 153can be formed to cover at least part of the first electrode 140 and theconnection electrode 145. As a result, a flip-chip type light emittingdiode chip as shown in FIGS. 24( a) and 24(b) is provided.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another. The second insulation layer 153can be formed of or include a different material than the firstinsulation layer 151. For example, the first insulation layer 151 caninclude SiO₂ and the second insulation layer 153 can include SiN_(x). Inaddition, the first insulation layer 151 can have a greater thicknessthan the second insulation layer 153. When the first insulation layer151 has a relatively large thickness, the light emitting structure 120can be more effectively protected from electrostatic discharge and canbe prevented from being damaged by external moisture.

The second insulation layer 153 can be formed by various methodsdepending upon formation materials. For example, the second insulationlayer 153 can be formed by deposition. Further, a fifth opening 153 aand a sixth opening 153 b can be formed by partially etching the secondinsulation layer 153. Alternatively, the fifth opening 153 a and thesixth opening 153 b can be formed by a lift-off process after depositionof the second insulation layer 153.

The second insulation layer 153 can include the fifth opening 153 a thatpartially exposes the first electrode 140 and the sixth opening 153 bthat partially exposes the connection electrode 145. The portions of thefirst electrode 140 and the connection electrode 145 respectivelyexposed through the fifth opening 153 a and the sixth opening 153 b canprovide regions to be electrically connected to an external power sourceduring the operation of the light emitting diode chip. Thus, the lightemitting diode chip according to this exemplary embodiment does notinclude bumps, and thus can be used in various application ranges thatrequire a slim light emitting diode chip.

When external power is supplied to the light emitting diode chip throughthe first electrode 140 and the connection electrode 145, light isemitted through recombination of holes and electrons in the activeregion 123 of the light emitting diode region LR. On the other hand,since the protective diode region PR is connected to the light emittingdiode region LR in reverse parallel, the light emitting diode chip doesnot emit light even upon application of electric power thereto.Accordingly, in operation of the light emitting diode chip, since lightis not generated in the protective diode region PR, a dark portion iscreated in a region in which the protective diode region PR is placed.

On the other hand, the growth substrate 110 can be removed from thefirst conductive type semiconductor layer 121. The growth substrate 110can be removed from the light emitting structure 120 by a technologyknown to those skilled in the art. The growth substrate 110 can beseparated or removed from the light emitting structure by aphysical/chemical process, for example, laser lift-off, chemicallift-off, stress lift-off, or polishing, and the like.

Next, the light emitting diode chip according to this exemplaryembodiment will be described. Here, repeated descriptions of componentshaving the same reference numerals as those of the aforementionedexemplary embodiment will be omitted.

The light emitting diode chip according to the exemplary embodimentincludes a light emitting diode region LR and a protective diode regionPR connected to the light emitting diode region LR in reverse parallel.Here, the protective diode region PR can be placed at a central portionof the light emitting diode chip and can be disposed to be surrounded bythe light emitting diode region LR.

Each of the light emitting diode region LR and the protective dioderegion PR can include the first conductive type semiconductor layer 121,and mesas M1 and M2 disposed on the first conductive type semiconductorlayer 121 and including the active layer 123 and the second conductivetype semiconductor layer 125 disposed on the active layer 123. The mesasM1 and M2 can include a first mesa M1 disposed on the light emittingdiode region LR and a second mesa M2 disposed on the protective dioderegion PR.

Furthermore, the light emitting diode chip can include a secondelectrode 130 disposed on the mesas M1 and M2, a first insulation layer151 covering the second electrode 130 and the mesas M1 and M2 andincluding openings that partially expose the first conductive typesemiconductor layer 121 and the second electrode 130, a first electrode140, and a connection electrode 145. Here, the first conductive typesemiconductor layer 121 of the light emitting diode region LR can beelectrically connected to the second electrode 130 of the protectivediode region PR by the first electrode 140, and the first conductivetype semiconductor layer 121 of the protective diode region PR can beelectrically connected to the first conductive type semiconductor layer121 of the light emitting diode region LR by the connection electrode145. With this structure, the light emitting diode region LR and theprotective diode region PR can be connected to each other in reverseparallel.

Further, the light emitting diode chip can further include a secondinsulation layer 153, which partially covers the first electrode 140 andthe connection electrode 145 and includes openings partially exposingthe first electrode 140 and the connection electrode 145.

As such, according to the exemplary embodiment, a flip-chip type lightemitting diode chip including the protective diode region PR and thelight emitting diode region LR in one chip can be provided. With such alight emitting diode chip, it is possible to prevent damage to the lightemitting diode due to electrostatic discharge without a separateprotection device.

FIGS. 25( a) and 25(b) represent a plan view and a sectional view of alight emitting diode chip and a method for manufacturing the sameaccording to some embodiments.

The light emitting diode chip according to the exemplary embodiment ofFIG. 25 is generally similar to the light emitting diode chip shown inFIG. 24, and further includes a first electrode pad 161 and a secondelectrode pad 163. Hereinafter, different features of the light emittingdiode chip according to this exemplary embodiment will be mainlydescribed and detailed descriptions of the same features will beomitted.

Referring to FIGS. 25( a) and 25(b), in addition to the features of thelight emitting diode chip shown in FIGS. 24( a) and 24(b), the lightemitting diode chip according to this exemplary embodiment can furtherinclude the first electrode pad 161 and the second electrode pad 163.

The first electrode pad 161 and the second electrode pad 163 can beformed on the second insulation layer 153. The first electrode pad 161can fill the fifth opening 153 a to be electrically connected to thefirst electrode 140, and the second electrode pad 163 can fill the sixthopening 153 b to be electrically connected to the connection electrode145. Accordingly, the first and second electrode pads 161 and 163 canserve as electrodes through which electric power is supplied from anexternal power source to the light emitting diode. In addition, thefirst electrode pad 161 can be electrically insulated from the secondelectrode pad 163 and can be separated therefrom.

The first electrode pad 161 and the second electrode pad 163 can includea bonding layer, such as a Ti, Cr or Ni layer, and a highly conductivelayer such as an Al, Cu, Ag or Au layer. The first electrode pad 161 andthe second electrode pad 163 can be formed on the second insulationlayer 153 by plating or depositing these metals. In addition, the firstelectrode pad 161 and the second electrode pad 163 can be formed at thesame time by the same process, without being limited thereto.

FIGS. 26( a) and 26(b) represent a plan view and a sectional view of alight emitting diode chip and a method for manufacturing the sameaccording to some embodiments.

The light emitting diode chip according to the exemplary embodimentshown in FIGS. 26( a) and 26(b) are generally similar to the lightemitting diode chip shown in FIGS. 25( a) and 25(b), and furtherincludes a heat dissipation pad 170. Hereinafter, different features ofthe light emitting diode chip according to this exemplary embodimentwill be mainly described and detailed descriptions of the same featureswill be omitted.

Referring to FIGS. 26( a) and 26(b), the light emitting diode chipfurther includes the heat dissipation pad 170 in addition to thefeatures of the light emitting diode chip of FIGS. 25( a) and 25(b).

The heat dissipation pad 170 can be formed on the second insulationlayer 153 and can be electrically insulated from the light emittingstructure 120. In addition, the heat dissipation pad 170 can be disposedbetween the first and second electrode pads 161 and 163, and can beelectrically insulated from the bumps 171 and 173. The heat dissipationpad 170 can be formed by plating or deposition of a material having highthermal conductivity, for example, Cu.

The light emitting diode chip according to this exemplary embodimentincludes the heat dissipation pad 170 to allow effective heatdissipation upon light emission, and can improve lifespan andreliability of a high output large flip-chip type light emitting diodechip.

FIG. 27 to FIG. 29 are a sectional view, a perspective view and anenlarged sectional view of a light emitting device according to someembodiments. Specifically, FIG. 27 and FIG. 28 are a sectional vied anda perspective view of the light emitting device, and FIG. 28 is anenlarged view of section X of FIG. 27.

The light emitting device according to this exemplary embodimentincludes a light emitting diode chip 500 and a lens 300. The lightemitting device can further include a substrate 410 supporting the lightemitting diode chip 500, and a reflective sheet 420.

The light emitting diode chip 500 can be or include a flip-chip typelight emitting diode chip which includes a light emitting diode regionand a protective diode region connected to the light emitting diode inreverse parallel. For example, the light emitting diode chip 500 can beor include a light emitting diode in which the light emitting dioderegion and the protective diode region are formed in a single chip.Further, since the light emitting diode chip 500 has a flip-chipstructure, the light emitting diode chip 500 can omit a wire forelectrically connecting the light emitting diode chip 500 to thesubstrate 210.

The light emitting diode chip 500 can include the light emitting diodechips according to the exemplary embodiment of FIGS. 24( a) and 24(b),FIGS. 25( a) and 25(b) or FIGS. 26( a) and 26(b). As shown in FIG. 29,the light emitting diode chip 500 according to this exemplary embodimentwill be described as the light emitting diode chip shown in FIGS. 24( a)and 24(b). Accordingly, in the light emitting diode chip 500, theprotective diode region PR can be placed at the center thereof. However,it should be understood that the present disclosure is not limitedthereto and other implementations are also possible. Variousmodifications can be made to the light emitting diode chips withoutdeparting from the scope of the disclosure.

The substrate 410 can be or include a conductive or insulatingsubstrate, and can include, for example, a polymer substrate, a ceramicsubstrate, a metal substrate, or a printed circuit board. In addition,the flip-chip type light emitting diode chip 500 is mounted on thesubstrate 410 and thus can act as a chip mounting member. Further, thesubstrate 410 can act as a support member on which the lens 300 will beseated.

The substrate 410 can include leads (not shown) that can be electricallyconnected to the flip-chip type light emitting diode. When the substrate410 is a printed circuit board, printed circuits can correspond to theleads.

For example, as shown in FIG. 29, the light emitting diode chip 500 canbe mounted on the substrate 410, and the first electrode 140 and theconnection electrode 145 can be bonded onto the substrate via conductivebonding materials 411 and 413 such as solders. Here, the substrate 410is electrically connected to the light emitting diode chip 500 by theconductive bonding materials 411 and 413. When the substrate 410includes the leads, the conductive bonding materials 411 and 413 cancontact the leads to electrically connect the substrate 410 to the lightemitting diode chip 500.

The reflective sheet 420 can be placed near a side surface of the lightemitting diode chip 500 between the lens 300 and the substrate 410, andcan contact the side surface of the light emitting diode chip 500. Thereflective sheet 420 can be coated with a white reflective materialhaving high reflectivity in order to reflect light in a wide wavelengthrange of visible light. Accordingly, the reflective sheet 420 canreflect light into the lens 300.

The lens 300 can include a lower surface 330 and an upper surface 340,and can further include a flange 350.

The lower surface 330 of the lens 300 can be formed with a lower concavesection 320, and the light emitting diode chip 500 can be disposed underthe lower concave section 320. Alternatively, the light emitting diodechip 500 can be placed within the lower concave section 320.

An inner surface of the lower concave section 320 is defined as a lightincident face 330 through which light emitted from the light emittingdiode chip 500 is incident on the lens 300. The light incident face 330includes a side surface 331 and can further include a top surfacedisposed on the side surface 331. The lower concave section 320 can havea shape, the width of which is gradually decreased upwards from a lowerentrance such that the side surface 331 of the light incident face 330has a slope. Here, the side surface 331 can have a shape in which aninclination of a tangent line thereof decreases. Alternatively, the sidesurface can have a shape in which the inclination of the tangent linethereof is constant or increases.

The top surface 333 of the light incident face 330 can have a flat shapesuch that the lower concave section 320 can have a truncated verticallysectional shape, without being limited thereto. Alternatively, the topsurface 333 of the light incident face 330 can have a convex shape.

The upper surface 340 of the lens 300 is configured to allow lighthaving entered the lens 300 and discharged from the lens 300 to have awide beam angle and uniform beam distribution. As shown, the uppersurface 340 of the lens 300 can include an upper concave section 342,which can be placed in a central region of the lens 300 and can includea central portion 345 at the center thereof. In addition, the uppersurface 340 of the lens 300 can further include an inner surface 341surrounding the central portion 345 of the upper concave section and anouter surface 343 surrounding the inner surface 341.

Each of the inner surface 341 and the outer surface 343 can have aconvex shape. An inclination of a tangent line on the inner surface 341can be opposite to the inclination of the tangent line on the outersurface 343. For example, in a certain shape where the lower surface ofthe lens 300 is defined as the x-axis and a virtual central axis V isdefined as the y-axis, the inclination of the inner surface 341 can havea positive value and the inclination of the outer surface 343 can have anegative value. Accordingly, a height of an adjoining portion betweenthe inner surface 341 and the outer surface 343 can correspond to thehighest point of the lens 300. However, it should be understood that thepresent disclosure is not limited thereto and other implementations arealso possible. The shape of the upper surface can be modified in variousways by taking into account the beam angle and the like.

By the upper concave section 342 and the inner surface 341 of the uppersurface 340, light traveling near the central region of the lens 300 isdistributed outwards, and the outer surface 343 increases the intensityof light emitted outwards from the central axis V of the lens 300. Inaddition, the light emitting diode generally has the highest intensityof light travelling in an upward direction perpendicular to the lightemitting diode. According to the exemplary embodiment, the lens 300 hasthe upper concave section 342 at the center thereof such that lighttravelling in the upward direction perpendicular to the light emittingdiode can be scattered or reflected towards the side surface thereof,thereby relieving concentration of light on the central region of thelight emitting device. In summary, light having entered the lens 300 anddischarged therefrom can have a wide beam angle and uniform beamdistribution.

On the other hand, the upper concave section 342 of the lens 300 can beplaced above the light emitting diode chip 500, for example, above theprotective diode region. When the protective diode region is place atthe center of the light emitting diode chip 500, the upper concavesection 342 can be placed at the center of the upper surface 340 of thelens 300. In addition, both the central portion 345 of the upper concavesection and the protective diode region can be disposed on the centralaxis V.

Hereinafter, this structure will be described in more detail withreference to FIG. 29. The protective diode region PR of the lightemitting diode chip 500 is placed at the center of the light emittingdiode. In addition, the upper concave section 342 is placed at thecenter of the lens 300. Accordingly, the protective diode region PR andthe central portion 345 of the upper concave section 342 can be alignedon the virtual central axis V of the lens perpendicular to the uppersurface of the light emitting diode chip 500.

As described above, the lens 300 according to the exemplary embodimentscatters or reflects light, which travels in the upward directionperpendicular to the light emitting diode chip 500, towards the sidesurface thereof, thereby preventing concentration of light on an upperportion of the central region of the light emitting device. That is,since light emitted through the center of the light emitting diode chipis guided to travel in a different direction by the lens 300 instead oftraveling in the upward direction perpendicular to the light emittingdiode, the light emitting device does not suffer from deterioration inluminous uniformity due to the intensity of light emitted from thecenter of the light emitting diode chip, thereby providing wide anduniform beam distribution of light. Further, the light emitting deviceaccording to the exemplary embodiment can more effectively preventconcentration of light above the center of the lens 300 upon lightemission.

Accordingly, the location of the protective diode region PRcorresponding to the dark portion of the light emitting diode chip 500in which light is not generated is aligned perpendicular to the centralportion 345 of the upper concave section of the lens 300, therebyminimizing deterioration in luminous uniformity caused by the darkportion of the light emitting diode chip 500.

Furthermore, the light emitting diode chip 500 includes the protectivediode region, thereby eliminating a need for a separate protectiondevice, for example, a Zener diode, on the substrate 210. Accordingly,the light emitting device can be manufactured by a simple process withreduced manufacturing costs, thereby improving yield of the lightemitting device.

Referring again to FIG. 27 and FIG. 28, the flange 350 can be disposedbetween the upper surface 340 and the lower surface 330, and defines thesize of the lens 300. The flange 350 can have a convex-concave patternon a side surface and a lower surface thereof, thereby improving lightextraction efficiency of the lens 300. Although not shown in thedrawings, the flange 350 can be further formed with a leg at a lowerside thereof such that the leg is coupled to the substrate 210 to holdthe lens 300.

FIG. 30 is a sectional view of a light emitting device according to someembodiments.

Referring to FIG. 30, a light emitting device according to someembodiments includes a light emitting diode 100 c and a substrate 600.The light emitting diode 100 c is disposed on the substrate 600, and forexample, can be mounted on the substrate 600.

The light emitting diode 100 c can include a light emitting structure120, a first electrode pad 161, a second electrode pad 163, and a heatdissipation pad 170. The light emitting diode 100 c can further includean insulation layer 150. In some implementations, the substrate 600 caninclude a base 610, a conductive pattern 630, and an insulation pattern620 placed in at least some region between the base 610 and theconductive pattern 630. Further, the base 610 can include a post 613extending in an upward direction of the substrate 600. Here, thesubstrate 600 includes grooves 611 formed between the post 613 and theconductive pattern 630 to separate the post 613 and the conductivepattern 630 from each other.

First, the light emitting diode 100 c will be described hereinafter.

The light emitting diode 100 c can include a light emitting structure.The light emitting structure 120 includes a first conductive typesemiconductor layer, a second conductive type semiconductor layer, andan active layer disposed between the first conductive type semiconductorlayer and the second conductive type semiconductor layer to emit light.As for the structure of the light emitting structure 120, any structureallowing a first electrode pad 161 and a second electrode pad 163 to beelectrically connected to a lower side thereof can be used withoutlimitation. For example, the light emitting structure 120 can be orinclude a light emitting structure suitable for a flip-chip type lightemitting diode.

The first electrode pad 161 and the second electrode pad 163 can extenddownwards from a lower surface of the light emitting structure 120. Thefirst electrode pad 161 and the second electrode pad 163 can beseparated from each other to be insulated from each other and can beelectrically connected to different polarities. For example, the firstelectrode pad 161 can be electrically connected to an N-typesemiconductor layer of the light emitting structure 120 and the secondelectrode pad 163 can be electrically connected to a P-typesemiconductor layer of the light emitting structure 120.

The first electrode pad 161 and the second electrode pad 163 can bedisposed on the conductive pattern 630 and electrically connected toeach other. The conductive pattern 630 can include a first conductivepattern and a second conductive pattern separated from each other to beelectrically insulated from each other, in which the first electrode pad161 and the second electrode pad 163 are respectively disposed on thefirst conductive pattern and the second conductive pattern to beelectrically connected to each other.

Each of the first electrode pad 161 and the second electrode pad 163 canbe bonded to the conductive pattern 630 using, for example, a solder ora conductive bonding adhesive. Alternatively, the first electrode pad161 and the second electrode pad 163 can include a solder layer. Whenthe first and second electrode pads include the solder layer, a separateadhesive material can be omitted.

The first electrode pad 161 can be placed near one side of a lowersurface of the light emitting structure 120, and the second electrodepad 163 can be placed near the other side of the lower surface of thelight emitting structure 120. In this structure, as shown in thedrawings, a certain space can be defined between the first electrode pad161 and the second electrode pad 163. The heat dissipation pad 170 canbe disposed in this space. Accordingly, the heat dissipation pad 170 canbe disposed between the first electrode pad 161 and the second electrodepad 163. However, it should be understood that the present disclosure isnot limited thereto and other implementations are also possible.Arrangement of the first and second electrode pads 161 and 163 and theheat dissipation pad 170 can be changed in various ways as needed.

The first electrode pad 161 and the second electrode pad 163 can includea conductive material such as a metal. For example, the first electrodepad 161 and the second electrode pad 163 can include Ni, Pt, Pd, Rh, W,Ti, Al, Ag, Sn, Cu, Ag, Bi, In, Zn, Sb, Mg, or Pb, and the like.Further, each of the first electrode pad 161 and the second electrodepad 163 can be composed of a single layer or multiple layers.

The heat dissipation pad 170 can serve to dissipate heat from the lightemitting structure 120 to the outside of the light emitting structure120. The heat dissipation pad 170 can extend downwards from a lowersurface of the light emitting structure 120. Further, the heatdissipation pad 170 can be physically connected to the light emittingstructure 120 while being electrically insulated therefrom. As the heatdissipation pad 170 is physically connected to the light emittingstructure 120, heat generated from the light emitting structure 120 canbe transferred to the heat dissipation pad 170.

Since the heat dissipation pad 170 physically connected to the lightemitting structure 120, heat dissipation efficiency of the lightemitting diode can increase with increasing area of the heat dissipationpad 170. Thus, a contact area between the heat dissipation pad 170 andthe light emitting structure 120 can be greater than the contact areabetween the first electrode pad 161 and/or the second electrode pad 163and the light emitting structure 120. Further, since the heatdissipation pad 170 is disposed between the first electrode pad 161 andthe second electrode pad 16, the heat dissipation pad 170 is disposedunder a central portion of the light emitting structure 120. However, itshould be understood that the present disclosure is not limited theretoand other implementations are also possible. Arrangement of the heatdissipation pad 170, the first electrode pad 161 and the secondelectrode pad 163 can be changed in various ways as needed.

The heat dissipation pad 170 can include a material having relativelyhigh thermal conductivity, for example, Ag, Cu, Au, Al, or Mo, and thelike. In some implementations, the heat dissipation pad 170 can havehigher thermal conductivity than the first electrode pad 161 and thesecond electrode pad 163. That is, the first electrode pad 161 and thesecond electrode pad 163 can have higher electrical conductivity thanthe heat dissipation pad 170, and the heat dissipation pad 170 can havehigher thermal conductivity than the first electrode pad 161 and thesecond electrode pad 163.

The light emitting diode 100 c can further include the insulation layer150, which insulates the light emitting structure 120 from the heatdissipation pad 170. The insulation layer 150 can include asilicon-based insulation material such as SiO_(x) and SiN_(x), and/or aninsulation material such as MgF₂, and can include another insulationmaterial having good thermal conductivity. Further, the insulation layercan include a distributed Bragg reflector in which materials havingdifferent indexes of refraction are alternately stacked one aboveanother.

Since the insulation layer 150 is disposed between the heat dissipationpad 170 and the light emitting structure 120, the heat dissipation pad170 can be formed of or include a material having high thermalconductivity without significant consideration of electricalconductivity.

As such, since heat dissipation pad 170 is insulated from the lightemitting structure 120 by the insulation layer 150, it is possible tominimize electrical problems such as short circuit by the heatdissipation pad 170 during operation of the light emitting device. Atthe same time, the heat dissipation pad 170 is connected to the lightemitting structure 120 with the insulation layer 150 interposedtherebetween, so that heat generated in the light emitting structure 120can be effectively transferred to the heat dissipation pad 170, therebyimproving heat dissipation efficiency of the light emitting diode 100 c.

The substrate 600 includes the base 610 and the conductive pattern 630,and can further include an insulation pattern 620. Further, the base 610includes the post 613 and the substrate 600 can further include grooves611 separating the post 613 from the conductive pattern 630.

The base 610 can act as a supporter of the substrate 600 and include ametallic material. For example, the base 610 can include a materialhaving good thermal conductivity. The base 610 can include a metallicmaterial such as Ag, Cu, Au, Al, or Mo, and the like, and can becomposed of a single layer or multiple layers.

Further, the base 610 can directly contact the heat dissipation pad 170.In this structure, the base 610 can contact the post 613.

An upper surface of the post 613 can be generally flush with an uppersurface of the conductive pattern 630. Accordingly, when the lightemitting diode 100 c is mounted on the substrate 600, stable contactbetween the base 610 and the heat dissipation pad 170 can be secured.

With the structure wherein the heat dissipation pad 170 directlycontacts the base 610 including a metal having good thermalconductivity, the light emitting device can effectively transfer heatfrom light emitting diode 100 c to the base 610 upon operation of thelight emitting diode. Since the base 610 can act as a supporter of thesubstrate 600, heat transferred to the base 610 can be effectivelydischarged to the outside. Accordingly, the light emitting device canhave improved heat dissipation efficiency.

According to the exemplary embodiment, the heat dissipation pad 170physically connected to the light emitting structure 120 is physicallyconnected to the base 610 of the substrate 600, thereby enabling veryeffective dissipation of heat upon light emission. Thus, it is possibleto solve a problem of deterioration in thermal conductivity between thebase of the substrate and the light emitting diode in the related art.

The post 613 of the base 610 is separated from the conductive pattern630 by the grooves 611. Accordingly, since the heat dissipation pad 170can be more effectively prevented from being electrically connected tothe conductive pattern 630, it is possible to prevent electricalproblems such as short circuit during operation of the light emittingdevice. Further, the grooves 611 are formed in the substrate 600 in thecourse of mounting the light emitting diode 100 c on the substrate 600,so that the heat dissipation pad 170 is prevented from beingelectrically connected to the first and second electrode pads 161 and163 by a bonding material such as solders, thereby improving processyield in manufacture of the light emitting device. Furthermore, thelight emitting device according to the exemplary embodiment can bemanufactured without a process of forming a bonding material such assolder cream, thereby simplifying the process of manufacturing the lightemitting device. In some embodiments, the grooves 611 can be filled withan insulation material.

The conductive pattern 630 can be disposed on the base 610 and can beelectrically connected to the first and second electrode pads 161 and163. Accordingly, the conductive pattern 630 can include a firstconductive pattern electrically connected to the first electrode pad 161and a second conductive pattern electrically connected to the secondelectrode pad 163, in which the first and second conductive patterns canbe separated to be insulated from each other. As shown in FIG. 30, thefirst electrode pad 161 and the second electrode pad 163 can be disposedon the conductive pattern 630 to be electrically connected to eachother.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. In someembodiments, the light emitting device includes a plurality ofconductive patterns 630. The conductive pattern 630 can be modified invarious ways depending on the number and shape of bumps of the lightemitting diode 100 c. The conductive pattern 630 can serve as anelectrical circuit, and can also act as a lead of the light emittingdevice.

The conductive pattern 630 can be disposed at locations corresponding tothe first and second electrode pads 161, 163, and the post of the base610 can be disposed at a location corresponding to the heat dissipationpad 170. Further, an upper surface of the conductive pattern 630 can besubstantially flush with an upper surface of the post. With thisstructure, the light emitting diode 100 c can be stably mounted on anupper surface of the substrate 600.

When the base 610 has electrical conductivity, the insulation pattern620 can be disposed between the base 610 and the conductive pattern 630to insulate the base 610 from the conductive pattern 630.

According to this exemplary embodiment, the substrate 600 has astructure wherein the insulation pattern 620 and the conductive pattern630 are formed on the base 610. Accordingly, a typical process ofpatterning an insulation layer between bases can be omitted, therebylowering manufacturing costs of the light emitting device. In addition,the base 610 includes the post, which directly contacts the heatdissipation pad 170 of the light emitting diode 100 c, therebysignificantly improving heat dissipation efficiency.

On the other hand, although a single light emitting diode 100 c ismounted on the substrate 600 in this exemplary embodiment, the presentdisclosure is not limited thereto and other implementations are alsopossible. The light emitting device according to exemplary embodimentscan include a plurality of light emitting diodes 100 c mounted on thesubstrate 600. The plurality of light emitting diodes 100 c can beelectrically connected to each other in series, in parallel, or inreverse parallel. Electrical connection between the plurality of lightemitting diodes 100 c can be achieved by the conductive pattern 630.Here, the conductive pattern 630 can act as an electrical circuit.

FIG. 31 is a sectional view of a light emitting device according to someembodiments.

The light emitting device shown in FIG. 31 is generally similar to thelight emitting device shown in FIG. 30 excluding an integral structureof the heat dissipation pad and a first electrode pad 161 a.Hereinafter, different features of the light emitting device shown inFIG. 31 will be mainly described and detailed descriptions of the samefeatures will be omitted.

Referring to FIG. 31, the light emitting device according to someembodiments includes a light emitting diode 100 c and a substrate 600.The light emitting diode 100 c is disposed on the substrate 600, and forexample, can be mounted on the substrate 600.

The light emitting diode 100 c includes a light emitting structure 120,a first electrode pad 161 a, and a second electrode pad 163. Thesubstrate 600 can include a base 610, a conductive pattern 630, and aninsulation pattern 620 placed in at least some region between the base610 and the conductive pattern 630. Further, the base 610 can include apost 613 extending in an upward direction of the substrate 600. Here,the substrate 600 includes grooves 611 formed between the post 613 andthe conductive pattern 630 to separate the post 613 and the conductivepattern 630 from each other.

Since the first electrode pad 161 a is integrally formed with the heatdissipation pad, the first electrode pad 161 a can contact theconductive pattern 630 and the post 613. Accordingly, the firstelectrode pad 161 a has a larger width than the second electrode pad163, so that a contact area between the first electrode pad 161 a andthe light emitting structure 120 is greater than the contact areabetween the second electrode pad 163 and the light emitting structure120. For example, the contact area between the first electrode pad 161 aand the light emitting structure 120 can be two times or larger thecontact area between the second electrode pad 163 and the light emittingstructure 120. With the structure wherein the first electrode pad 161 ais integrally formed with the heat dissipation pad, the groove 611between the conductive pattern 630 and the post 613 contacting the firstelectrode pad 161 a can be at least partially covered by the firstelectrode pad 161 a.

The first electrode pad 161 a contacts the post 613 of the substrate 600while partially contacting the conductive pattern 630 to act as anelectrode of the light emitting diode and as a heat dissipation pad atthe same time. Particularly, the contact area between the firstelectrode pad 161 a and the light emitting structure 120 can be greaterthan the contact area between the second electrode pad 163 and the lightemitting structure 120, thereby significantly improving heat dissipationcharacteristics of the light emitting device.

The first electrode pad 161 a can be or include a bump electricallyconnected to an N-type semiconductor layer of the light emittingstructure 120 and thus is connected to an N-type of an external powersource during operation of the light emitting device. Upon injection ofelectric current injected into the light emitting diode, currentspreading efficiency is higher in an area around an N-type bump than inan area around a P-type bump. Accordingly, in this exemplary embodiment,the contact area between the first electrode pad 161 a electricallyconnected to the N-type semiconductor layer and the light emittingstructure 120 is increased, thereby improving current spreadingefficiency of the light emitting diode. Thus, according to thisexemplary embodiment, it is possible to provide a light emitting devicehaving improved current spreading efficiency and heat dissipationefficiency.

FIG. 32 is a sectional view of a light emitting device according to someembodiments.

The light emitting device shown in FIG. 32 is generally similar to thelight emitting device shown in FIG. 2 except that the thickness of theheat dissipation pad 170 is greater than the thicknesses of the firstand second electrode pads 161 and 163. Hereinafter, different featuresof the light emitting device shown in FIG. 32 will be mainly describedand detailed descriptions of the same features will be omitted.

Referring to FIG. 32, the light emitting device according to someembodiments includes a light emitting diode 100 c and a substrate 600.The light emitting diode 100 c is disposed on the substrate 600, and forexample, can be mounted on the substrate 600.

The light emitting diode 100 c includes a light emitting structure 120,a first electrode pad 161, a second electrode pad 163, and a heatdissipation pad 170. The light emitting diode 100 c can further includean insulation layer 150. The substrate 600 can include a base 610, aconductive pattern 630, and an insulation pattern 620 placed in at leastsome region between the base 610 and the conductive pattern 630.Further, the base 610 can include a post 613 extending in an upwarddirection of the substrate 600. Here, the substrate 600 includes grooves611 formed between the post 613 and the conductive pattern 630 toseparate the post 613 and the conductive pattern 630 from each other.

The heat dissipation pad 170 a can have a greater thickness than thefirst electrode pad 161 and the second electrode pad 163, whereby alower surface of the heat dissipation pad 170 a can be placed lower thanlower surfaces of the first and second electrode pads 161 and 163.Corresponding to this structure, an upper surface of the post 613 a ofthe substrate 600 can be placed lower than an upper surface of theconductive pattern 630.

With the structure wherein the heat dissipation pad 170 a has arelatively great thickness, it is possible to enhance heat dissipationefficiency of the light emitting diode 100 c. Furthermore, the height ofthe post 613 a of the substrate 600 is adjusted corresponding to thethickness of the heat dissipation pad 170 a, thereby preventing unstablemounting of the light emitting diode due to difference in height in thecourse of mounting the light emitting diode 100 c on the substrate 600.Furthermore, with the structure wherein the post 613 a has a low height,it is possible to facilitate alignment of the light emitting diode 100 cin the course of mounting the light emitting diode 100 c.

FIG. 33 is a sectional view of a light emitting device according to someembodiments.

The light emitting device shown in FIG. 33 is generally similar to thelight emitting device shown in FIG. 2 excluding the structure and shapeof a substrate 700. Hereinafter, different features of the lightemitting device shown in FIG. 33 will be mainly described and detaileddescriptions of the same features will be omitted.

Referring to FIG. 33, the light emitting device according to someembodiments includes a light emitting diode 100 c and a substrate 700.The light emitting diode 100 c is disposed on the substrate 700, and forexample, can be mounted on substrate 700.

The light emitting diode 100 c includes a light emitting structure 120,a first electrode pad 161, a second electrode pad 163, and a heatdissipation pad 170. The light emitting diode 100 c can further includean insulation layer 150.

The substrate 700 can include a first lead 710, a second lead 720, aheat dissipation lead 730, and a base 740.

The base 740 can exhibit electrically insulating properties, andinclude, for example, ceramic or polymer materials. For example, thebase 740 can be or include a ceramic substrate having good thermalconductivity, whereby the light emitting device can have improved heatdissipation efficiency.

The first lead 710 can include a first upper conductive pattern 711, afirst lower conductive pattern 715, and a first via 713 through whichthe first upper and lower conductive patterns 711 and 715 areelectrically connected to each other. The first upper conductive pattern711 can be disposed on an upper surface of the base 740, the first lowerconductive pattern 715 can be disposed on a lower surface of the base740, and the first via 713 can be formed through the base 740 such thatthe first upper conductive pattern 711 can be electrically connected tothe first lower conductive pattern 715 therethrough.

Like the first lead 710, the second lead 720 can include a second upperconductive pattern 721, a second lower conductive pattern 725, and asecond via 723 through which the second upper and lower conductivepatterns 721 and 725 are electrically connected to each other. Thesecond upper conductive pattern 721 can be disposed on the upper surfaceof the base 740, the second lower conductive pattern 725 can be disposedon the lower surface of the base 740, and the second via 723 can beformed through the base 740 such that the second upper conductivepattern 721 can be electrically connected to the second lower conductivepattern 725 therethrough.

The first electrode pad 161 and the second electrode pad 163 arerespectively placed on the first lead 710 and the second lead 720 to beelectrically connected thereto. Thus, when the light emitting device ismounted on an additional substrate (for example, printed circuitsubstrate) and the like, the first lower conductive pattern 715 and thesecond lower conductive pattern 725 can be connected to an externalpower source to supply electric power to the light emitting diode 100 c.

The first lead 710 and the second lead 720 can include a material havinggood electrical conductivity. For example, the first lead 710 and thesecond lead 720 can be formed by deposition and/or plating a metallicmaterial such as Ni, Pt, Pd, Rh, W, Ti, Al, Ag, Au, or Cu, and the like.For example, the first and second upper conductive patterns 711 and 721can include a material having not only electrical conductivity but alsohigh reflectivity, for example, Au, Al, or Ag, and the like.

The heat dissipation lead 730 can include an upper heat dissipationpattern 731 disposed on the upper surface of the base 740, a lower heatdissipation pattern 735 disposed on the lower surface of the base 740,and a heat dissipation via 733 through which the upper heat dissipationpattern 731 and the lower heat dissipation pattern 735 are thermallyconnected to each other. The heat dissipation via 733 can thermallyconnect the upper and lower heat dissipation patterns 731 and 735 toeach other through the base 740.

The heat dissipation lead 730 can contact the heat dissipation pad 170.Thus, the heat dissipation pad 170 can be placed on the heat dissipationlead 730 to be bonded thereto. With the structure wherein heat generatedfrom the light emitting diode 100 c upon light emission of the lightemitting diode 100 c can be transferred to the heat dissipation lead 730through the heat dissipation pad 170, the light emitting deviceaccording to the embodiments can have improve heat dissipationefficiency. Accordingly, the heat dissipation lead 730 can include amaterial having good thermal conductivity, for example, a metallicmaterial such as W, Au, and the like. However, it should be understoodthat the present disclosure is not limited thereto and otherimplementations are also possible.

On the other hand, an upper surface of the heat dissipation lead 730 canbe placed lower than upper surface of the leads 710 and 720. With thisstructure, the thickness of the heat dissipation pad 170 can be greaterthan the thicknesses of the first and second electrode pads 161 and 163,thereby improving heat dissipation efficiency of the light emittingdevice. Further, the base 740 can include grooves 741 disposed betweenthe leads 710 and 720 and the heat dissipation lead 730.

The heat dissipation lead 730 can act like a heat sink and thus allowseffective dissipation of heat generated upon operation of the lightemitting diode 100 c. For example, when the light emitting device ismounted on an additional substrate (for example, a printed circuitsubstrate) and the like, the heat dissipation lead 730, particularly,the lower heat dissipation pattern 735, can be connected to a heatdissipation member of the additional substrate.

FIG. 34 to FIG. 37 are plan views and sectional views of an exemplarylight emitting diode and an exemplary light emitting device according tosome embodiments.

FIG. 34 to FIG. 37 are plan views and sectional views of a lightemitting diode 100 g according to some embodiments. FIG. 34( a) is aplan view illustrating locations of a plurality of holes 127 a andconnection holes 127 b, and FIG. 34( b) is a bottom view of the lightemitting diode 100 g. FIG. 35 and FIG. 36 are cross-sectional viewstaken along lines A-A and B-B in the plan views of FIG. 34,respectively. FIG. 37 is a sectional view of the light emitting diode100 d mounted on a substrate 600. In description of the exemplaryembodiment of FIG. 34 to FIG. 37, detailed descriptions of the samecomponents as those of the light emitting diode according to theexemplary embodiment described with reference to FIG. 32 will beomitted.

Referring to FIG. 34 to FIG. 36, the light emitting diode 100 d includesa light emitting structure 120, which includes a first conductive typesemiconductor layer 121, an active layer 123 and a second conductivetype semiconductor layer 125, a second electrode 130, a first electrode140, a first insulation layer 151, a first electrode pad 161, a secondelectrode pad 163, and a heat dissipation pad 170. The light emittingdiode 100 d can further include a second insulation layer 153.

The light emitting structure 120 can include the first conductive typesemiconductor layer 121, the active layer 123 disposed on the firstconductive type semiconductor layer 121, and the second conductive typesemiconductor layer 125 disposed on the active layer 123. Further, thelight emitting structure 120 can include a plurality of holes 127 a,which are formed through the second conductive type semiconductor layer125 and the active layer 123 such that the first conductive typesemiconductor layer 121 is partially exposed therethrough, and canfurther include at least one connection hole 127 b connecting theplurality of holes 127 a to each other.

The first conductive type semiconductor layer 121, the active layer 123and the second conductive type semiconductor layer 125 can include aIII-V-based compound semiconductor, for example, a nitride semiconductorsuch as (Al, Ga, In)N. The first conductive type semiconductor layer 121can include an n-type impurity, for example, Si, and the secondconductive type semiconductor layer 125 can include a p-type impurity,for example, Mg, or vice versa. The active layer 123 can include amulti-quantum well (MQW) structure.

The plurality of holes 127 a can be formed by partially removing theactive layer 123 and the second conductive type semiconductor layer 125such that an upper surface of the first conductive type semiconductorlayer 121 is partially exposed therethrough. The number and location ofthe plural holes 127 are not particularly limited. For example, theholes 127 a can be arranged at regular intervals in the light emittingstructure 120, as shown in FIG. 34.

In addition, the plurality of holes 127 a can be connected to each otherby at least one connection hole 127 b, which is formed by partiallyremoving the active layer 123 and the second conductive typesemiconductor layer 125 such that the upper surface of the firstconductive type semiconductor layer 121 is partially exposedtherethrough. For example, as shown in FIG. 34, the plurality of holes127 a can be connected to each other by a plurality of connection holes127 b. At least some of the plurality of holes 127 a can be connected toeach other by the connection hole 127 b. For example, as in thisexemplary embodiment, all of the plurality of holes 127 a can beconnected to each other by the connection holes 127 b. However, itshould be understood that the present disclosure is not limited theretoand other implementations are also possible.

As described hereinafter, the first electrode 140 can form ohmic contactwith the first conductive type semiconductor layer 121 through the holes127 a. Accordingly, the plural holes 127 a are arranged at regularintervals in the light emitting structure 120, thereby allowing uniformcurrent spreading throughout the light emitting structure 120. Inaddition, the plural holes 127 a are connected by the connection hole127 b, whereby electric current can be substantially uniformly spreadthroughout the light emitting structure 120 instead of crowding at acertain hole 127 a.

The light emitting structure 120 can include a roughness R on an uppersurface thereof. The roughness R can be formed by dry etching, wetetching and/or electrochemical etching. For example, the roughness R canbe formed by wet etching the upper surface of the light emittingstructure 120 using a solution including at least one of KOH or NaOH, orby PEC etching. In some implementations, the roughness R can be formedby combination of wet etching and dry etching. It should be understoodthat these method for forming the roughness R are provided forillustration only, and the roughness R can be formed on the surface ofthe light emitting structure 120 using various methods known to thoseskilled in the art. The light emitting diode 100 d can have improvedlight extraction efficiency by forming the roughness R on the surface ofthe light emitting structure 120.

In this exemplary embodiment, a growth substrate is separated from thefirst conductive type semiconductor layer 121, whereby the upper surfaceof the first conductive type semiconductor layer 121 is exposed.However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. Namely, anadditional substrate such as the growth substrate can be additionallydisposed on the first conductive type semiconductor layer 121.

The second electrode 130 is disposed on the second conductive typesemiconductor layer 125. The second electrode 130 can partially cover alower surface of the second conductive type semiconductor layer 125while forming ohmic contact therewith. Further, the second electrode 130can be disposed to cover the lower surface of the second conductive typesemiconductor layer 125 and can be formed as a monolithic layer.Specifically, the second electrode 130 can be formed to cover theremaining region of the lower surface of the second conductive typesemiconductor layer 125 excluding regions in which the plurality ofholes 127 a and the connection structure 127 b are formed. With thisstructure, the light emitting diode can uniformly supply electriccurrent to the entirety of the light emitting structure 120, therebyimproving current spreading efficiency or current spreading performance.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. The secondelectrode 130 can be formed as a plurality of unit electrode layersdisposed on the lower surface of the second conductive typesemiconductor layer 125 instead of being formed as a monolithic layer.

The second electrode 130 can include a material capable of forming ohmiccontact with the second conductive type semiconductor layer 125, forexample, a metallic material and/or a conductive oxide.

When the second electrode 130 includes a metallic material, the secondelectrode 130 can include a reflective layer and a cover layer coveringthe reflective layer.

As described above, the second electrode 130 can form ohmic contact withthe second conductive type semiconductor layer 125 while acting as areflector reflecting light. Thus, the reflective layer can include ametal having high reflectivity and capable of forming ohmic contact withthe second conductive type semiconductor layer 125. For example, thereflective layer can include at least one of Ni, Pt, Pd, Rh, W, Ti, Al,Mg, Ag or Au. Further, the reflective layer can be composed of a singlelayer or multiple layers.

The cover layer can prevent inter-diffusion between the reflective layerand other materials, and thus can prevent damage to the reflective layerdue to diffusion of external materials into the reflective layer.Accordingly, the cover layer can be formed to cover a lower surface anda side surface of the reflective layer. The cover layer can beelectrically connected together with the reflective layer to the secondconductive type semiconductor layer 125 and thus can act as an electrodetogether with the reflective layer. The cover layer can include, forexample, Au, Ni, Ti, or Cr, and can be composed of a single layer ormultiple layers.

When the second electrode 130 can include a conductive oxide, theconductive oxide may include ITO, ZnO, AZO, or IZO, and the like.

The first insulation layer 151 can partially cover a lower surface ofthe light emitting structure 120 and the second electrode 130. In someimplementations, the first insulation layer 151 can partially fill theconnection hole 127 b to be interposed between the first conductive typesemiconductor layer 121 exposed through the connection hole 127 b andthe second electrode 130, and to be disposed in a region between thefirst electrode 140 and the second electrode 130, which excludes theplurality of holes 127 a. In addition, the first insulation layer 151covers side surfaces of the plurality of holes 127 a while exposingupper surfaces of the 127 a to partially expose the first conductivetype semiconductor layer 121. Furthermore, the first insulation layer151 can also cover a side surface of the light emitting structure 120.

The first insulation layer 151 can include first openings 151 a placedat portions corresponding to the plurality of holes 127 a and secondopenings 151 b that partially expose the second electrode 130. The firstconductive type semiconductor layer 121 can be partially exposed throughthe first openings 151 a and the holes 127 a, and the second electrode130 can be partially exposed through the second openings 151 b.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the first insulation layer 151 caninclude multiple layers, and can include a distributed Bragg reflectorin which materials having different indexes of refraction arealternately stacked one above another. In some implementations, when thesecond electrode 130 includes a conductive oxide, the first insulationlayer 151 can include the distributed Bragg reflector to improveluminous efficacy.

The first electrode 140 can be disposed on the lower surface of thelight emitting structure 120 and can fill the plurality of holes 127 aand the first openings 151 a to form ohmic contact with the firstconductive type semiconductor layer 121. The first electrode 140 can beformed to cover the entirety of the first insulation layer 151 excludingsome regions of the lower surface of the first insulation layer 151.Alternatively, although not shown in the drawings, the first electrode140 can be formed to cover the side surface of the light emittingstructure 120. When first electrode 140 is formed to cover the sidesurface of the light emitting structure 120, the first electrode 140reflects light emitted through the side surface of the light emittingstructure from the active layer 123 in an upward direction, therebyincreasing a ratio of light emitted through the upper surface of thelight emitting diode 100 b. On the other hand, the first electrode 140is not placed in a region corresponding to the second openings 151 b ofthe first insulation layer 151, and is insulated from the reflectivemetal layer 130.

The first electrode 140 is formed to cover the overall lower surface ofthe light emitting structure 120 excluding some regions, thereby furtherimproving current spreading efficiency or current spreading performance.In addition, since a portion of the light emitting structure 120 notcovered by the second electrode 130 can be covered by the firstelectrode 140, light can be more effectively reflected, therebyimproving luminous efficacy of the light emitting diode 100 d.

The first electrode 140 can form ohmic contact with the first conductivetype semiconductor layer 121 while acting as a reflector reflectinglight. Accordingly, the first electrode 140 can include a highlyreflective metal layer such as an Al layer. Here, the highly reflectivemetal layer can be formed on a bonding layer such as a Ti, Cr or Nilayer.

Since the first electrode 140 forms ohmic contact with the firstconductive type semiconductor layer 121 through the holes 127 a, regionsof the active layer 123 removed to form electrodes connected to thefirst conductive type semiconductor layer 121 are the same as theregions of the plurality of holes 127 a. This structure can minimize anarea of the first conductive type semiconductor layer 121 for ohmiccontact with the metal layer, thereby providing a light emitting diodehaving a relatively large area ratio of light emitting area to ahorizontal area of the overall light emitting structure.

The light emitting diode 100 d can further include the second insulationlayer 153. The second insulation layer 153 can cover the first electrode140. The second insulation layer 153 can include third openings 153 athat partially expose the first electrode 140, and fourth openings 153 bthat partially expose the second electrode 130. Here, the fourthopenings 153 b can be formed at locations corresponding to the secondopenings 151 b.

Each of the third and fourth openings 153 a and 153 b can be formed in asingular or plural numbers. In addition, when the third openings 153 aare placed near one side of the light emitting diode, the fourthopenings 153 b can be placed near the other side thereof.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The first electrode pad 161 can be disposed on a lower surface of thesecond insulation layer 153 and is electrically connected to the firstelectrode 140 through the third openings 153 a. The second electrode pad163 can be disposed on the lower surface of the second insulation layer153 and is electrically connected to the second electrode 130 throughthe fourth openings 153 b. Accordingly, the first and second electrodepads 161 and 163 are electrically connected to the first and secondconductive type semiconductor layers 121 and 125, respectively.Accordingly, the first and second electrode pads 161 and 163 can act aselectrodes through which electric power is supplied from an externalpower source to the light emitting diode.

The heat dissipation pad 170 can be disposed on the lower surface of thesecond insulation layer 153 and can extend to be disposed under thelight emitting structure 120. The heat dissipation pad 170 can bephysically connected to the light emitting structure 120 to dissipateheat from the light emitting structure 120 to the outside. Further, theheat dissipation pad 170 can be disposed between first electrode pad 161and the second electrode pad 163 to be disposed under a central portionof the light emitting structure 120. However, it should be understoodthat the present disclosure is not limited thereto and otherimplementations are also possible. Arrangement of the heat dissipationpad 170, the first electrode pad 161 and the second electrode pad 163can be changed in various ways as needed.

Referring to FIG. 36, a light emitting device including the lightemitting diode 100 d according to the exemplary embodiment can beprovided. As shown in FIG. 36, the light emitting diode 100 d can bedisposed on a substrate 600, and particularly, the heat dissipation pad170 can contact a post 613 a of the substrate 600.

According to this exemplary embodiment, the light emitting diode 100 dhas high current spreading efficiency or current spreading performanceto allow application of high electric current while securing high heatdissipation efficiency through the heat dissipation pad 170 even uponapplication of high electric current. Accordingly, the structure of thelight emitting diode according to this exemplary embodiment is verysuitable for a high output light emitting device.

FIG. 38 to FIG. 40 are plan views and sectional views of a lightemitting diode 100 e and a light emitting device according to someembodiments.

The light emitting diode 100 e shown in FIG. 38 to FIG. 40 is generallysimilar to the light emitting diode 100 d shown in FIG. 34 to FIG. 37except that the light emitting structure 120 includes mesas M and anexposed region of the first conductive type semiconductor layer 121 isformed around the mesas M. Hereinafter, different features of the lightemitting diode 100 e will be mainly described and detailed descriptionsof the same features will be omitted.

FIG. 38( a) is a bottom view of the light emitting diode 100 e, FIG. 38(b) is a plan view illustration locations of the mesas M and third andfourth openings 153 a and 153 b, FIG. 39 is sectional views taken alongline C-C of FIGS. 38( a) and 38(b), and FIG. 40 is a sectional view of alight emitting device including the light emitting diode 100 e.

Referring to FIG. 38 and FIG. 39, the light emitting diode 100 eaccording to some embodiments includes a light emitting structure 120,which includes a first conductive type semiconductor layer 121, anactive layer 123 and a second conductive type semiconductor layer 125, afirst electrode 140, a second electrode 130, a first insulation layer151, a first electrode pad 161, and a second electrode pad 163. Thelight emitting diode 100 e can further include a second insulation layer153 and growth substrate 110.

The light emitting structure 120 can include the first conductive typesemiconductor layer 121, the active layer 123 disposed on the firstconductive type semiconductor layer 121, and the second conductive typesemiconductor layer 125 disposed on the active layer 123. Further, thelight emitting structure 120 can include a partially exposed region ofthe first conductive type semiconductor layer 121 formed by partiallyremoving the second conductive type semiconductor layer 125 and theactive layer 123. For example, as shown in FIG. 38, the light emittingstructure 120 can include a plurality of mesas M including the secondconductive type semiconductor layer 125 and the active layer 123,whereby the partially exposed region of the first conductive typesemiconductor layer 121 is formed around the plurality of mesas M.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible. The shapesof the mesas M and the exposed region of the first conductive typesemiconductor layer 121 can be changed in various ways as needed.

The second electrode 130 can be disposed on the second conductive typesemiconductor layer 125 to form ohmic contact therewith. Accordingly,the second electrode 130 can be disposed on a lower surface of each ofthe mesas M. Alternatively, when the light emitting diode 100 e includesan integrated mesa M, The second electrode 130 can be formed as asingular electrode. Further, the second electrode 130 can be formed tocover most of the lower surface of the second conductive typesemiconductor layer 125, thereby providing uniform horizontal currentspreading in the second conductive type semiconductor layer 125.

The second electrode 130 can include a conductive material capable offorming ohmic contact with the second conductive type semiconductorlayer 125. For example, the second electrode 130 can include a metaland/or a conductive oxide. When the second electrode 130 includes ametal, the second electrode 130 can include a reflective layer and acover layer covering the reflective layer.

The first insulation layer 151 can partially cover the light emittingstructure 120 and the second electrode 130, and for example, can includefirst openings that partially expose the first conductive typesemiconductor layer 121 and second openings that partially expose thesecond electrode 130. The first electrode 140 described below can beelectrically connected to the first conductive type semiconductor layer121 through the first openings that partially expose the firstconductive type semiconductor layer 121 in the first insulation layer.Accordingly, locations of the first openings can be changed in variousways depending upon a contact area between the first electrode 140 andthe first conductive type semiconductor layer 121. For example, thefirst openings 140 can be formed along sides of the mesas M, as shown inthe drawings. Further, the second openings can be disposed on the mesasM, and locations of the second openings can be determined by taking intoaccount a region in which the second electrode pad 163 described belowwill be formed. For example, as shown in FIG. 38( b), the second openingcan be placed near one side of each of the mesas M.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). In addition, the first insulation layer 151can be composed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another. In some implementations, when thesecond electrode 130 includes a conductive oxide, light can be reflectedin an upward direction of the light emitting diode 100 e by the firstinsulation layer 151 including the distributed Bragg reflector.

The first electrode 140 can at least partially cover the firstinsulation layer 151, and can cover the overall upper surface of thelight emitting structure 120 excluding some regions. Further, the firstelectrode 140 can form ohmic contact with the first conductive typesemiconductor layer 121 through the openings that expose the firstconductive type semiconductor layer 121. On the other hand, the firstelectrode 140 is not formed on a region through which the secondelectrode 130 is exposed, whereby the first electrode 140 can beinsulated from the second electrode 130 by the first insulation layer151.

The first electrode 140 is formed to covers the overall lower surface ofthe light emitting structure 120 excluding some regions thereof, therebyenabling further improved uniform horizontal current spreading. Inaddition, since a portion of the light emitting structure 120 notcovered by the second electrode 130 can be covered by the firstelectrode 140, light traveling in a downward direction of the lightemitting diode 100 e can be more effectively reflected, therebyimproving luminous efficacy of the light emitting diode 100 e.

The second insulation layer 153 can cover the first electrode 140, andcan include a third opening 153 a and fourth openings 153 b thatpartially expose the first electrode 140 and the second electrode 130.

The third opening 153 a can partially expose the first electrode 140 andbe formed near one side of the light emitting diode 100 e, as shown inFIG. 38( b). Further, the fourth openings 153 b can partially expose thesecond electrode 130 and be formed near the other side of the lightemitting diode 100 e, as shown in FIG. 38( b). Furthermore, the fourthopening 153 b can be formed on each of the mesas M. However, it shouldbe understood that the present disclosure is not limited thereto andother implementations are also possible. The shapes of the third andfourth openings 153 a and 153 b can be changed in various ways asneeded.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The growth substrate 110 can be disposed on the light emitting structure120 and any substrate can be used as the growth substrate 110 so long asthe substrate allows growth of the light emitting structure 120 thereon.For example, the growth substrate 110 can include a sapphire substrate,a silicon carbide substrate, a silicon substrate, a gallium nitridesubstrate, or an aluminum nitride substrate, and the like. Inalternative embodiments, the growth substrate 110 can be omitted, andcan be separated and removed from the light emitting structure 120 by aphysical/chemical process, for example, laser lift-off, chemicallift-off, stress lift-off, thermal lift-off, or lapping, and the likeafter completion of growth of the light emitting structure 120.

When the growth substrate 110 is separated and removed from the lightemitting structure 120, the light emitting structure 120 can includeroughness R, as shown in FIG. 35.

The first electrode pad 161 and the second electrode pad 163 can beelectrically connected to the first electrode 140 and the secondelectrode 130 through the third opening 153 a and the fourth openings153 b, respectively. On the other hand, the heat dissipation pad 170 canbe disposed on the second insulation layer 153 between the first andsecond electrode pads 161 and 163. Accordingly, the heat dissipation pad170 can be physically connected to the light emitting structure 120while being electrically insulated therefrom.

Further, the heat dissipation pad 170 can be formed to a greaterthickness than the first and second electrode pads 161 and 163, therebyimproving heat dissipation efficiency through the heat dissipation pad170.

Referring to FIG. 40, a light emitting device including the lightemitting diode 100 e according to the exemplary embodiment can beprovided. As shown in FIG. 40, the light emitting diode 100 e can bedisposed on a substrate 600, and particularly, the heat dissipation pad170 can contact a post 613 a of the substrate 600.

According to this exemplary embodiment, the light emitting diode 100 ehas high current spreading efficiency or current spreading performanceto allow application of high electric current while securing high heatdissipation efficiency through the heat dissipation pad 170 even uponapplication of high electric current. Accordingly, the structure of thelight emitting diode according to this exemplary embodiment is verysuitable for a high output light emitting device.

FIG. 41 to FIG. 43 are plan views and sectional views of a lightemitting diode and a light emitting device according to someembodiments.

A light emitting diode 100 f shown in FIG. 41 to FIG. 43 is generallysimilar to the light emitting diode 100 d shown in FIG. 34 to FIG. 37except that the light emitting structure 120 includes at least one hole120 h that exposes the first conductive type semiconductor layer 121.Hereinafter, different features of the light emitting diode 100 f willbe mainly described and detailed descriptions of the same features willbe omitted.

FIG. 41( a) is a bottom view of the light emitting diode 100 f, FIG. 41(b) is a plan view illustration locations of the hole 120 h and third andfourth openings 153 a and 153 b, FIG. 42 is a sectional views takenalong line D-D of FIGS. 41( a) and 41(b), and FIG. 43 is a sectionalview of a light emitting device including the light emitting diode 100f.

Referring to FIGS. 41 and 42, the light emitting diode 100 f accordingto some embodiments includes a light emitting structure 120, whichincludes a first conductive type semiconductor layer 121, an activelayer 123 and a second conductive type semiconductor layer 125, a firstelectrode 140, a second electrode 130, a first insulation layer 151, afirst electrode pad 161, and a second electrode pad 163. The lightemitting diode 100 f can further include a second insulation layer 153and a growth substrate 110.

The light emitting structure 120 can include the first conductive typesemiconductor layer 121, the active layer 123 disposed on the firstconductive type semiconductor layer 121, and the second conductive typesemiconductor layer 125 disposed on the active layer 123. Further, thelight emitting structure 120 can include a partially exposed region ofthe first conductive type semiconductor layer 121 formed by partiallyremoving the second conductive type semiconductor layer 125 and theactive layer 123. For example, as shown in FIG. 41, the light emittingstructure 120 can include at least one hole 120 h that is formed throughthe second conductive type semiconductor layer 125 and the active layer123 to exposes the first conductive type semiconductor layer 121.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible, arrangementand the number of holes 120 h can be changed in various ways as needed.

The second electrode 130 can be disposed on the second conductive typesemiconductor layer 125 to form ohmic contact therewith. The secondelectrode 130 can be formed to cover the overall lower surface of thesecond conductive type semiconductor layer 125, thereby enabling furtherimproved uniform horizontal current spreading in the second conductivetype semiconductor layer 125.

The second electrode 130 can include a conductive material capable offorming ohmic contact with the second conductive type semiconductorlayer 125. For example, the second electrode 130 can include a metaland/or a conductive oxide. When the second electrode 130 includes ametal, the second electrode 130 can include a reflective layer and acover layer covering the reflective layer.

The first insulation layer 151 can partially cover the light emittingstructure 120 and the second electrode 130, and particularly, caninclude a first opening that partially exposes the first conductive typesemiconductor layer 121 and a second opening that partially exposes thesecond electrode 130. The first electrode 140 described below can beelectrically connected to the first conductive type semiconductor layer121 through the first openings that partially expose the firstconductive type semiconductor layer 121 in the first insulation layer.Accordingly, the first opening can be placed corresponding to a regionin which the at least one hole 120 h is formed, and the first insulationlayer 151 can cover a side surface of the hole 120 h. The second openingcan be placed on the second conductive type semiconductor layer 125, andthe location of the second opening can be determined by taking intoaccount a region in which the second electrode pad 163 described belowwill be formed.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). In addition, the first insulation layer 151can be composed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another. Particularly, when the secondelectrode 130 includes a conductive oxide, light can be reflected in anupward direction of the light emitting diode 100 f by the firstinsulation layer 151 including the distributed Bragg reflector.

The first electrode 140 can at least partially cover the firstinsulation layer 151, and can cover the overall upper surface of thelight emitting structure 120 excluding some regions. Further, the firstelectrode 140 can form ohmic contact with the first conductive typesemiconductor layer 121 through the hole 120 h and the openings thatexpose the first conductive type semiconductor layer 121. On the otherhand, the first electrode 140 is not formed on a region through whichthe second electrode 130 is exposed, whereby the first electrode 140 canbe insulated from the second electrode 130 by the first insulation layer151.

The first electrode 140 is formed to covers the overall lower surface ofthe light emitting structure 120 excluding some regions thereof, therebyenabling further improved uniform horizontal current spreading. Inaddition, since a portion of the light emitting structure 120 notcovered by the second electrode 130 can be covered by the firstelectrode 140, light traveling in a downward direction of the lightemitting diode 100 f can be more effectively reflected, therebyimproving luminous efficacy of the light emitting diode 100 f.

The second insulation layer 153 can cover the first electrode 140, andcan include a third opening 153 a and fourth openings 153 b thatpartially expose the first electrode 140 and the second electrode 130.

The third opening 153 a can partially expose the first electrode 140 andbe formed near one side of the light emitting diode 100 f, as shown inFIG. 41( b). Further, the fourth openings 153 b can partially expose thesecond electrode 130 and be formed near the other side of the lightemitting diode 100 f, as shown in FIG. 41( b). However, it should beunderstood that the present disclosure is not limited thereto and otherimplementations are also possible. The shapes of the third and fourthopenings 153 a and 153 b can be changed in various ways as needed.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The growth substrate 110 can be disposed on the light emitting structure120 and any substrate can be used as the growth substrate 110 so long asthe substrate allows growth of the light emitting structure 120 thereon.For example, the growth substrate 110 can include a sapphire substrate,a silicon carbide substrate, a silicon substrate, a gallium nitridesubstrate, an aluminum nitride substrate, and the like. In alternativeembodiments, the growth substrate 110 can be omitted, and can beseparated and removed from the light emitting structure 120 by aphysical/chemical process, for example, laser lift-off, chemicallift-off, stress lift-off, thermal lift-off, lapping, and the like aftercompletion of growth of the light emitting structure 120.

When the growth substrate 110 is separated and removed from the lightemitting structure 120, the light emitting structure 120 can includeroughness R, as shown in FIG. 35.

The first electrode pad 161 and the second electrode pad 163 can beelectrically connected to the first electrode 140 and the secondelectrode 130 through the third opening 153 a and the fourth openings153 b, respectively. On the other hand, the heat dissipation pad 170 canbe disposed on the second insulation layer 153 between the first andsecond electrode pads 161 and 163. Accordingly, the heat dissipation pad170 can be physically connected to the light emitting structure 120while being electrically insulated therefrom.

Further, the heat dissipation pad 170 can be formed to a greaterthickness than the first and second electrode pads 161 and 163, therebyimproving heat dissipation efficiency through the heat dissipation pad170.

Referring to FIG. 43, a light emitting device including the lightemitting diode 100 f according to the exemplary embodiment can beprovided. As shown in FIG. 43, the light emitting diode 100 f can bedisposed on a substrate 600, and particularly, the heat dissipation pad170 can contact a post 613 a of the substrate 600.

According to this exemplary embodiment, the light emitting diode 100 fhas high current spreading efficiency or current spreading performanceto allow application of high electric current while securing high heatdissipation efficiency through the heat dissipation pad 170 even uponapplication of high electric current. Accordingly, the structure of thelight emitting diode according to this exemplary embodiment is verysuitable for a high output light emitting device.

FIG. 44 to FIG. 47 are plan views and sectional views of a lightemitting diode and a light emitting device according to someembodiments.

A light emitting diode 100 d shown in FIG. 44 to FIG. 47 is generallysimilar to the light emitting diode 100 f shown in FIG. 41 to FIG. 43

light emitting diode 100 f except that the second electrode 130 includesa plurality of unit contact electrodes 131 u. Hereinafter, differentfeatures of the light emitting diode 100 g will be mainly described anddetailed descriptions of the same features will be omitted.

FIG. 44( a) is a bottom view of the light emitting diode 100 g, FIG. 44(b) is a plan view illustration locations of the hole 120 h, the unitcontact electrodes 131 u, and third and fourth openings 153 a and 153 b,FIG. 45 is a sectional view taken along line E-E of FIGS. 44( a) and44(b), FIG. 46 is a sectional view taken along line F-F of FIGS. 44( a)and 44(b), and FIG. 47 is a sectional view of a light emitting deviceincluding the light emitting diode 100 g.

Referring to FIG. 44 to FIG. 46, the light emitting diode 100 gaccording to some embodiments includes a light emitting structure 120, afirst electrode 140, a second electrode 130, a first insulation layer151, a first electrode pad 161, and a second electrode pad 163. Thelight emitting diode 100 g can further include a second insulation layer153 and a growth substrate 110.

The light emitting structure 120 can include a partially exposed regionof the first conductive type semiconductor layer 121 formed by partiallyremoving the second conductive type semiconductor layer 125 and theactive layer 123. For example, as shown in FIG. 44, the light emittingstructure 120 can include at least one hole 120 h that is formed throughthe second conductive type semiconductor layer 125 and the active layer123 to exposes the first conductive type semiconductor layer 121.

However, it should be understood that the present disclosure is notlimited thereto and other implementations are also possible, arrangementand the number of holes 120 h can be changed in various ways as needed.

The second electrode 130 can be disposed on the second conductive typesemiconductor layer 125 to form ohmic contact therewith. Particularly,the second electrode 130 can further include a contact layer 131 and afirst connection layer 135, and can further include second connectionlayer 133. Hereinafter, the second electrode 130 will be described inmore detail.

The contact layer 131 can be formed as a plurality of unit contactelectrodes 131 u separated from each other. The plurality of unitcontact electrodes 131 u can be electrically connected to each other bythe first connection layer 135 and the second connection layer 133 canconnect the unit contact electrodes 131 u to the first connection layer135.

Each of the unit contact electrodes 131 u includes an openingcorresponding to the at least one hole 120 h. Namely, the at least onehole 120 h can be exposed through the opening, and the width and area ofthe opening of the each of the unit contact electrodes 131 u can belarger than those of the hole 120 h. Each of the unit contact electrodes131 u can be regularly disposed on the light emitting structure 120 tohave substantially the same area and/or shape. For example, as shown inFIG. 44, the unit contact electrodes 131 u can be disposed in a latticearrangement. With the structure wherein the plurality of unit contactelectrodes 131 u forming ohmic contact with the second conductive typesemiconductor layer 125 have substantially the same area and/or shape,it is possible to achieve generally uniform current spreading withrespect to the entirety of the light emitting structure 120. The openingof each of the unit contact electrodes 131 u can be placed at a centralportion of each of the unit contact electrodes 131 u, whereby each ofthe holes 120 h can be placed at the central portion of each of the unitcontact electrodes 131 u.

In operation of the light emitting diode according to this exemplaryembodiment, the first conductive type semiconductor layer 121 formsohmic contact with the first electrode 140 through the plurality ofholes 120 h and the second conductive type semiconductor layer 121 formsohmic contact therewith through the respective unit contact electrodes131 u. Accordingly, electric current can be supplied to the first andsecond conductive type semiconductor layers 121 and 125 through thethrough the plural holes 120 h and the unit contact electrodes 131 u,and the hole 120 h is placed at the central portion of each of the unitcontact electrodes 131 u, thereby allowing uniform current spreading inthe light emitting structure under the unit contact electrodes 131 u.Such unit contact electrodes 131 u and the holes 127 are regularlyarranged on the light emitting structure, thereby providing uniformcurrent spreading with respect to a light emitting area of the entiretyof the light emitting structure.

A reflective electrode layer 131 includes a reflective layer and a coverlayer covering the reflective layer.

On the other hand, the first connection layer 135 electrically connectsthe plurality of unit contact electrodes 131 u to each other, therebyallowing current spreading to the unit contact electrodes 131 u uponoperation of the light emitting diode 100 g. Further, the secondconnection layer 133 can reduce ohmic resistance between the firstconnection layer 135 and the unit contact electrodes 131 u. The secondconnection layer 133 and the first connection layer 135 can beintegrally formed with each other through the same process and includethe same material. Alternatively, the second connection layer 133 andthe first connection layer 135 can be sequentially formed throughseparate processes and can include different materials. Here, the secondconnection layer 133 and the first connection layer 135 can include aconductive material, for example, a metal.

The first insulation layer 151 can partially cover the light emittingstructure 120 and the second electrode 130, and particularly, caninclude a first opening that partially exposes the first conductive typesemiconductor layer 121 and a second opening that partially expose thesecond electrode 130. The first electrode 140 described below can beelectrically connected to the first conductive type semiconductor layer121 through the first opening that partially exposes the firstconductive type semiconductor layer 121 in the first insulation layer.Accordingly, the first opening can be placed corresponding to a regionin which the at least one hole 120 h is formed, and the first insulationlayer 151 can cover a side surface of the hole 120 h, first insulationlayer 151. The second opening can be placed on the second conductivetype semiconductor layer 125, and the location of the second opening canbe determined by taking into account a region in which the secondelectrode pad 163 described below will be formed.

The first insulation layer 151 can include an insulation material, forexample, SiO₂ or SiN_(x). In addition, the first insulation layer 151can be composed of multiple layers, and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another. Particularly, when the secondelectrode 130 includes a conductive oxide, light can be reflected in anupward direction of the light emitting diode 100 g by the firstinsulation layer 151 including the distributed Bragg reflector.

The first electrode 140 can at least partially cover the firstinsulation layer 151, and can cover the overall upper surface of thelight emitting structure 120 excluding some regions. Further, the firstelectrode 140 can form ohmic contact with the first conductive typesemiconductor layer 121 through the hole 120 h and the openings thatexpose the first conductive type semiconductor layer 121. On the otherhand, the first electrode 140 is not formed on a region through whichthe second electrode 130 is exposed, whereby the first electrode 140 canbe insulated from the second electrode 130 by the first insulation layer151.

The first electrode 140 is formed to covers the overall lower surface ofthe light emitting structure 120 excluding some regions thereof, therebyenabling further improved uniform horizontal current spreading. Inaddition, since a portion of the light emitting structure 120 notcovered by the second electrode 130 can be covered by the firstelectrode 140, light traveling in a downward direction of the lightemitting diode 100 g can be more effectively reflected, therebyimproving luminous efficacy of the light emitting diode 100 g.

The second insulation layer 153 can cover the first electrode 140, andcan include a third opening 153 a and fourth openings 153 b thatpartially expose the first electrode 140 and the second electrode 130.

The third opening 153 a can partially expose the first electrode 140 andbe formed near one side of the light emitting diode 100 g, as shown inFIG. 44( b). Further, the fourth openings 153 b can partially expose thesecond electrode 130 and be formed near the other side of the lightemitting diode 100 f, as shown in FIG. 44( b). However, it should beunderstood that the present disclosure is not limited thereto and otherimplementations are also possible. The shapes of the third and fourthopenings 153 a and 153 b can be changed in various ways as needed.

The second insulation layer 153 can include an insulation material, forexample, SiO₂ or SiN_(x). Further, the second insulation layer 153 canbe composed of multiple layers and can include a distributed Braggreflector in which materials having different indexes of refraction arealternately stacked one above another.

The growth substrate 110 can be disposed on the light emitting structure120 and any substrate can be used as the growth substrate 110 so long asthe substrate allows growth of the light emitting structure 120 thereon.For example, the growth substrate 110 can include a sapphire substrate,a silicon carbide substrate, a silicon substrate, a gallium nitridesubstrate, an aluminum nitride substrate, and the like. In alternativeembodiments, the growth substrate 110 can be omitted, and can beseparated and removed from the light emitting structure 120 by aphysical/chemical process, for example, laser lift-off, chemicallift-off, stress lift-off, thermal lift-off, lapping, and the like aftercompletion of growth of the light emitting structure 120.

When the growth substrate 110 is separated and removed from the lightemitting structure 120, the light emitting structure 120 can includeroughness R, as shown in FIG. 35.

The first electrode pad 161 and the second electrode pad 163 can beelectrically connected to the first electrode 140 and the secondelectrode 130 through the third opening 153 a and the fourth openings153 b, respectively. On the other hand, the heat dissipation pad 170 canbe disposed on the second insulation layer 153 between the first andsecond electrode pads 161 and 163. Accordingly, the heat dissipation pad170 can be physically connected to the light emitting structure 120while being electrically insulated therefrom.

Further, the heat dissipation pad 170 can be formed to a greaterthickness than the first and second electrode pads 161 and 163, therebyimproving heat dissipation efficiency through the heat dissipation pad170.

Referring to FIG. 47, a light emitting device including the lightemitting diode 100 g according to the exemplary embodiment can beprovided. As shown in FIG. 47, the light emitting diode 100 g can bedisposed on a substrate 600, and particularly, the heat dissipation pad170 can contact a post 613 a of the substrate 600.

According to this exemplary embodiment, the light emitting diode 100 ghas high current spreading efficiency or current spreading performanceto allow application of high electric current while securing high heatdissipation efficiency through the heat dissipation pad 170 even uponapplication of high electric current. Accordingly, the structure of thelight emitting diode according to this exemplary embodiment is verysuitable for a high output light emitting device.

Only a few embodiments, implementations and examples are described andother embodiments and implementations, and various enhancements andvariations can be made based on what is described and illustrated inthis document.

What is claimed is:
 1. A light emitting device comprising: a substrateincluding a base and a conductive pattern disposed over the base; and alight emitting structure formed over the substrate and including a lightemitting structure, and a first electrode pad, a second electrode padand a heat dissipation pad extending under the light emitting structure,the light emitting structure including: a first conductive typesemiconductor layer; an active layer disposed under the first conductivetype semiconductor layer; a second conductive type semiconductor layerdisposed under the active layer; an exposed region partially formed onthe lower surface of the first conductive type semiconductor layer bypartially removing the active layer and the second conductive typesemiconductor layer; a first electrode forming ohmic contact with thefirst conductive type semiconductor layer through the exposed region ofthe first conductive type semiconductor layer; a second electrodeforming ohmic contact with the second conductive type semiconductorlayer; and a first insulation layer partially covering the secondelectrode, wherein the first electrode pad is electrically connected tothe first electrode, the second electrode pad is electrically connectedto the second electrode, the heat dissipation pad is electricallyinsulated from the light emitting structure, the base includes a postand a groove separating the post from the conductive pattern, the heatdissipation pad contacts an upper surface of the post, and the firstelectrode pad and the second electrode pad contact the conductivepattern.
 2. The light emitting device of claim 1, wherein the uppersurface of the post is placed lower than an upper surface of theconductive pattern.
 3. The light emitting device of claim 2, wherein theheat dissipation pad has a greater thickness than the first electrodepad and the second electrode pad.
 4. The light emitting device of claim1, wherein the conductive pattern includes a first conductive patternand a second conductive pattern that are separated from each other, thefirst electrode pad and the second electrode pad being disposed over thefirst and second conductive patterns, respectively.
 5. The lightemitting device of claim 4, wherein the heat dissipation pad is disposedbetween the first electrode pad and the second electrode pad.
 6. Thelight emitting device of claim 1, further comprising: an insulationlayer disposed between the heat dissipation pad and the light emittingstructure.
 7. The light emitting device of claim 1, wherein thesubstrate further includes a heat dissipation lead, is the heatdissipation lead including an upper heat dissipation pattern disposedover the upper surface of the post, a lower heat dissipation patterndisposed over a lower surface of the base, and a heat dissipation viaformed through the base and thermally connecting the upper and lowerheat dissipation patterns to each other.
 8. The light emitting device ofclaim 7, wherein the substrate further includes a first lead and asecond lead, the first lead including a first upper conductive patterndisposed over an upper surface of the base, a first lower conductivepattern disposed over the lower surface of the base, and a first viadisposed through the base and electrically connecting the first upperconductive pattern and the first lower conductive pattern to each other,the second lead including a second upper conductive pattern disposedover the upper surface of the base, a second lower conductive patterndisposed over the lower surface of the base, and a second via disposedthrough the base and electrically connecting the second upper conductivepattern and the second lower conductive pattern to each other, and theconductive pattern including the first upper conductive pattern and thesecond upper conductive pattern.
 9. The light emitting device of claim1, wherein the light emitting structure further includes a secondinsulation layer partially covering the first electrode, and the heatdissipation electrode is disposed over the second insulation layer andelectrically insulated from the light emitting structure.
 10. The lightemitting device of claim 1, wherein the partially exposed region of thefirst conductive type semiconductor layer includes a plurality of holesexposing the first conductive type semiconductor layer.
 11. The lightemitting device of claim 10, further comprising: at least one connectionhole connecting at least two of the plurality of holes.
 12. The lightemitting device of claim 10, wherein the second electrode includes aplurality of unit contact electrodes separated from each other, each ofthe unit contact electrodes including an opening exposing the hole. 13.The light emitting device of claim 12, further comprising: an extensionlayer electrically connecting the plurality of unit contact electrodesto each other.
 14. The light emitting device of claim 8, wherein thelight emitting structure includes at least one mesa including the secondconductive type semiconductor layer and the active layer, and theexposed region of the first conductive type semiconductor layer isdisposed around the mesa.
 15. The light emitting device of claim 4,wherein the first electrode pad and the heat dissipation pad areintegrally formed with each other, the first electrode pad contactingthe first conductive pattern and the upper surface of the post, thesecond electrode pad contacting the second conductive pattern.
 16. Thelight emitting device of claim 1, wherein the heat dissipation padphysically contacts with the light emitting structure.
 17. The lightemitting device of claim 16, wherein the heat dissipation pad physicallycontacts with the base.
 18. The light emitting device of claim 1,wherein the first electrode pad and the second electrode pad have higherelectrical conductivity than the heat dissipation pad, and the heatdissipation pad has higher thermal conductivity than the first electrodepad and the second electrode pad.
 19. The light emitting device of claim1, wherein the base includes a metallic material including Ag, Cu, Au,Al, or Mo.
 20. The light emitting device of claim 1, wherein the uppersurface of the post is flush with an upper surface of the conductivepattern.